diff --git a/lib/update.js b/lib/update.js
index 175d74e78c..b6ed6a44c1 100644
--- a/lib/update.js
+++ b/lib/update.js
@@ -7,248 +7,28 @@ var url = require("url");
 
 var ProgressBar = require('progress');
 
-var updater = require(path.join(__dirname, "..", "lib", "updater.js"));
-var files = require(path.join(__dirname, "..", "lib", "files.js"));
+var files = require('./files.js');
+var warehouse = require('./warehouse.js');
 
 var _ = require('underscore');
 
-// refuse to update if we're in a git checkout.
-if (files.in_checkout()) {
-  console.log("Your Meteor installation is a git checkout. Update it " +
-              "manually with 'git pull'.");
-  process.exit(1);
-}
-
 // XXX update for engine
 var updateMeteor = function () {
-  // Immediately kick off manifest check.
-  // XXX error check
-  var manifest = updater.getManifest();
-
-  //// Examine manifest and see if we need to upgrade.
-
-  if (!manifest || !manifest.version || !manifest.urlbase) {
-    console.log("Failed to download manifest.");
-    return;
-  }
-
-  if (!updater.needs_upgrade(manifest)) {
-    if (manifest.version === updater.ENGINE_VERSION) {
-      console.log("Already at current version: " + manifest.version);
-    } else {
-      console.log("Not upgrading. Your version: " + updater.ENGINE_VERSION
-                  + ". New version: " + manifest.version + ".");
-    }
-    return;
-  }
-
-  console.log("New version available: " + manifest.version);
-
-  //// Setup post-upgrade function so we can call it later
-  var post_remove_directories = [];
-  var cleanup_temp_dirs = function () {
-    _.each(post_remove_directories, files.rm_recursive);
-    post_remove_directories = [];
-  };
-
-  var run_post_upgrade = function () {
-    cleanup_temp_dirs();
-
-    // Launch post-upgrade script
-    var nodejs_path = path.join(files.get_dev_bundle(), 'bin', 'node');
-    var postup_path = path.join(files.getCurrentEngineDir(), 'meteor', 'post-upgrade.js');
-
-    if (fs.existsSync(nodejs_path) && fs.existsSync(postup_path)) {
-      // setup environment.
-      var modules_path = path.join(files.get_dev_bundle(), 'lib', 'node_modules');
-      var env = _.extend({}, process.env);
-      env.NODE_PATH = modules_path;
-
-      // launch it.
-      var postup_proc = spawn(nodejs_path, [postup_path], {env: env});
-      postup_proc.stderr.setEncoding('utf8');
-      postup_proc.stderr.on('data', function (data) {
-        process.stderr.write(data);
-      });
-      postup_proc.stdout.setEncoding('utf8');
-      postup_proc.stdout.on('data', function (data) {
-        process.stdout.write(data);
-      });
-    } else {
-      // no postup. Still print a message, but one that is subtly
-      // different so developers can debug what is going on.
-      console.log("upgrade complete.");
-    }
-  };
-
-  var run_with_root = function (cmd, args) {
-    if (0 === process.getuid()) {
-      // already root. just spawn the command.
-      return spawn(cmd, args);
-    } else if (fs.existsSync("/bin/sudo") ||
-               fs.existsSync("/usr/bin/sudo")) {
-      // spawn a sudo
-      console.log("Since this system includes sudo, Meteor will request root privileges to");
-      console.log("install. You may be prompted for a password. If you prefer to not use");
-      console.log("sudo, please re-run this command as root.");
-      console.log("sudo", cmd, args.join(" "));
-      return spawn('sudo', [cmd].concat(args));
-    }
-
-    // no root, no sudo. fail
-    console.log("Meteor requires root privileges to install. Please re-run this command");
-    console.log("as root.");
+  // refuse to update if we're in a git checkout.
+  if (!files.usesWarehouse()) {
+    console.log("Your Meteor installation is a git checkout. Update it " +
+                "manually with 'git pull'.");
     process.exit(1);
-    return null; // unreached, but makes js2 mode happy.
-  };
-
-
-  //// Figure out what platform we're upgrading on (dpkg, rpm, tar)
-
-  var package_stamp_path = path.join(files.get_dev_bundle(), '.package_stamp');
-  var package_stamp;
-  try {
-    package_stamp = fs.readFileSync(package_stamp_path, 'utf8');
-    package_stamp = package_stamp.replace(/^\s+|\s+$/g, '');
-  } catch (err) {
-    // no package stamp, assume tarball.
-    package_stamp = 'tar';
   }
 
-  var download_url; // url to download
-  var download_callback; // callback to call with path on disk of download.
-
-  var arch = os.arch();
-  var deb_arch;
-  var rpm_arch;
-  if ("ia32" == arch) {
-    deb_arch = "i386";
-    rpm_arch = "i386";
-    arch = "i686";
-  } else if ("x64" == arch) {
-    deb_arch = "amd64";
-    rpm_arch = "x86_64";
-    arch = "x86_64";
+  // XXX make errors look good
+  var updated = warehouse.fetchLatestRelease();
+  if (updated) {
+    console.log("Updated Meteor to release " + warehouse.latestRelease());
   } else {
-    console.log("Unsupported architecture", arch);
-    return;
+    console.log("Meteor release " + warehouse.latestRelease() +
+                " is already the latest release.");
   }
 
-  if ('deb' === package_stamp) {
-    download_url =
-      manifest.urlbase + "/meteor_" + manifest.deb_version +
-      "_" + deb_arch + ".deb";
-
-    download_callback = function (deb_path) {
-      var proc =  run_with_root('dpkg', ['-i', deb_path]);
-      proc.on('exit', function (code, signal) {
-        if (code !== 0 || signal) {
-          console.log("failed to install deb");
-          return;
-        }
-        // success!
-        run_post_upgrade();
-      });
-    };
-
-  } else if ('rpm' === package_stamp) {
-    download_url =
-      manifest.urlbase + "/meteor-" + manifest.rpm_version +
-      "." + rpm_arch + ".rpm";
-
-    download_callback = function (rpm_path) {
-      var proc = run_with_root('rpm', ['-U', '--force', rpm_path]);
-      proc.on('exit', function (code, signal) {
-        if (code !== 0 || signal) {
-          console.log("Error: failed to install Meteor RPM package.");
-          return;
-        }
-        // success!
-        run_post_upgrade();
-      });
-    };
-
-  } else {
-
-    download_url =
-      manifest.urlbase + "/meteor-package-" + os.type() +
-      "-" + arch + "-" + manifest.version + ".tar.gz";
-
-    download_callback = function (tar_path) {
-      var base_dir = path.join(__dirname, "..");
-      var tmp_dir = path.join(base_dir, "tmp");
-      // XXX error check!
-      try { fs.mkdirSync(tmp_dir, 0755); } catch (err) { }
-
-      try {
-        console.log('installing upgrade...');
-        files.extractTarGz(fs.readFileSync(tar_path),
-                           tmp_dir);
-      } catch (e) {
-        console.log(e);
-        console.log("Error: package download failed.");
-        return;
-      }
-
-      // untar complete. swap directories
-      var old_base_dir = base_dir + ".old";
-      if (fs.existsSync(old_base_dir))
-        files.rm_recursive(old_base_dir); // rm -rf !!
-
-      fs.renameSync(base_dir, old_base_dir);
-      fs.renameSync(path.join(old_base_dir, "tmp", "meteor"), base_dir);
-
-      // success!
-      run_post_upgrade();
-
-    };
-  }
-
-  //// Kick off download
-
-  var download_parsed = url.parse(download_url);
-  // XXX why is node's API for 'url' different from 'http'?
-  download_parsed.path = download_parsed.pathname;
-
-  var req = https.request(download_parsed, function(res) {
-    if (res.statusCode !== 200) {
-      console.log("Failed to download: " + download_url);
-      return;
-    }
-    var len = parseInt(res.headers['content-length'], 10);
-
-    var bar = new ProgressBar('  downloading [:bar] :percent', {
-      complete: '='
-      , incomplete: ' '
-      , width: 30
-      , total: len
-    });
-
-    // find / make directory paths
-    var tmp_dir = files.mkdtemp();
-    post_remove_directories.push(tmp_dir);
-
-    // open tempfile
-    var download_path = path.join(tmp_dir, path.basename(download_url));
-    var download_stream = fs.createWriteStream(download_path);
-
-    res.on('data', function (chunk) {
-      download_stream.write(chunk);
-      bar.tick(chunk.length);
-    });
-
-    res.on('end', function () {
-      download_stream.end();
-      console.log("... finished download");
-      // create a Fiber so that code in download_callback can use
-      // sync calls having Futures.
-      Fiber(function () {
-        download_callback(download_path);
-        // don't remove temp dir here, download_callback is probably still
-        // using it.
-      }).run();
-    });
-  });
-  req.end();
-
+  // XXX update app
 };
diff --git a/lib/warehouse.js b/lib/warehouse.js
index dfdeb6fc50..2d5bf73c48 100644
--- a/lib/warehouse.js
+++ b/lib/warehouse.js
@@ -69,13 +69,10 @@ var warehouse = module.exports = {
     var manifestPath = path.join(
       warehouse.getWarehouseDir(), 'releases', release + '.json');
 
-    if (fs.existsSync(manifestPath)) {
-      // read from warehouse
-      return JSON.parse(fs.readFileSync(manifestPath));
-    } else {
-      // grow warehouse with new manifest and packages
-      return warehouse._populateWarehouseForRelease(release);
-    }
+    warehouse._populateWarehouseForRelease(release);
+
+    // read from warehouse
+    return JSON.parse(fs.readFileSync(manifestPath));
   },
 
   _latestReleaseSymlinkPath: function () {
@@ -93,6 +90,7 @@ var warehouse = module.exports = {
     }
   },
 
+  // returns true if we updated the latest symlink
   // XXX make errors prettier
   fetchLatestRelease: function () {
     var manifest = updater.getManifest();
@@ -104,12 +102,18 @@ var warehouse = module.exports = {
     }
 
     warehouse._populateWarehouseForRelease(releaseName);
+
+    var storedLatestRelease = warehouse.latestRelease();
+    if (storedLatestRelease && storedLatestRelease === releaseName)
+      return false;
+
     var latestReleaseSymlink = warehouse._latestReleaseSymlinkPath();
     var tmpSymlink = latestReleaseSymlink + ".tmp" + warehouse._randomToken();
     // You can't directly symlink over an existing symlink, but you can rename
     // over it.
     fs.symlinkSync(releaseName, tmpSymlink);
     fs.renameSync(tmpSymlink, latestReleaseSymlink);
+    return true;
   },
 
   packageExistsInWarehouse: function (name, version) {
@@ -127,13 +131,15 @@ var warehouse = module.exports = {
   // fetches the manifest file for the given release version. also fetches
   // all of the missing versioned packages referenced from the release manifest
   // @param releaseVersion {String} eg "0.1"
-  // @returns {Object} release manifest
   _populateWarehouseForRelease: function(releaseVersion) {
     var future = new Future;
     var releasesDir = path.join(warehouse.getWarehouseDir(), 'releases');
     files.mkdir_p(releasesDir, 0755);
     var releaseManifestPath = path.join(releasesDir, releaseVersion + '.json');
 
+    if (fs.existsSync(releaseManifestPath))
+      return;
+
     // get release manifest, but only write it after we're done
     // writing packages
     var releaseManifest;
@@ -195,9 +201,6 @@ var warehouse = module.exports = {
     // now that we have written all packages, it's safe to write the
     // release manifest
     fs.writeFileSync(releaseManifestPath, JSON.stringify(releaseManifest));
-
-    // return manifest
-    return releaseManifest;
   },
 
   // @param packagesToPopulate {Object} eg {"less": "0.5.0"}