OS X Keyboard Consistency
OS X applications lack consistency in the way they handle the keyboard. It seems like every application has a different set of keystrokes for extremely common operations. By common operations, I mean things that devs do every day: next word, previous word, beginning of line, end of line, top of document, bottom of document.
There’s been some discussion of this on the Carbon-Dev list, recently. In my opinion, all applications should support the BBEdit bindings for navigating and selecting text, and also Emacs bindings like Control-A and Control-E that are easy to type with one hand.