Version 2: A really dirty version of one of the previous icons - created by someone (sorry can't find your name now) - and I really liked the "text document" icon in the background, so I just added the 'mate', so that it became an obvious TextMate.
I really like this, and the notion of having a text document somewhere (this would also accord with Apple Icon Dogma too, I think), but maybe things could be simplified even further by beheading Goofy Robot Guy, and placing his severed head next to the text document instead of the pen? This sort of makes a kind of metaphorical sense, I think, since both the pen and Goofy Robot Guy represent tools with which the document can be edited. (And of course braces or some other representation of structured text could be added to the text document itself.)
Marcin