This is done by overloading performKeyEquivalent: for the main menu (by setting it to OakMainMenu in MainMenu.xib).
The default implementation of performKeyEquivalent: does not know about scope selectors so it will sometimes call the wrong actions. For example a bundle overloading ⌘X for “-dyn.selection” may still see the item fire with a selection.
This wasn’t a problem previously, as we set the key equivalents via (deprecated) Carbon API (so presumably Cocoa didn’t know about the keys).
This is a preliminary implementation, I just want it out there to have it tested for edge-cases. Long-term we can probably remove the overload of performKeyEquivalent: on OakTextView, which sort of does similar (stops Cocoa from executing the wrong menu actions or interfering with multi-stroke key bindings).
Despite Menlo having been the new system font for fixed width text in the past several OS versions, NSFont’s userFixedPitchFontOfSize: still return Monaco, unless we build with the 10.8 SDK (and no, setting the deployment target to 10.7 does not produce something that actually runs on 10.7, at least not last I checked).
The disadvantage with Monaco as default font is that we lack bold and italic styles (since CoreText doesn’t synthesize these, unlike the legacy text rendering API TextMate 1.x used).
