A big difference between Emacs and Raskins' design is the concept of modelessness. If you've ever typed META+X in emacs in anticipation of typing a command, and then switched windows or got distracted or clicked the mouse, emacs is left in the 'command mode' and will misinterpret your next input.

Raskin coined the term 'pseudo-mode'. The difference between a pseudo-mode and a mode is the difference between the SHIFT key and the CAPS-LOCK key (for entering uppercase letters). The latter frustrates while the former goes unnoticed because it works so well.

If you are in any way involved with usability, read The Humane Interface: http://en.wikipedia.org/wiki/The_Humane_Interface