@ipstenu: love that you’re backing us up, but in this case the criticism is completely valid.
@kmessinger: you’re right, and it was our intention. It does actually work from fullscreen if you’re in HTML mode. It also works if you are in visual mode *if you are outside the editing box*. I know, that’s lame, but what can I say… TinyMCE has rules. 🙂
Hopefully in a future version ESC will also work from within the visual editor box.