Some kind soul on #textmate clued me in to the fact that the key here is to get Fink's /sw/bin/init.sh/csh to run ONLY when there's a TTY attached. That way, all the initialization stuff TextMate sucks in behind the scenes won't cause it to hang/SPOD when you pick New From Template -> Blogging Bundle -> HTML Post from the menu.
For zsh users like myself, the fix was simple, stick the test -r /sw/bin/init.sh && . /sw/bin/init.sh line Fink wants you to put in your shell init into the .zshenv file.
-Chris