Uhm... and more. :-) Former instructors and course visionaries are, too.
Not so incidentally, if you're the slightest bit interested in being a TA for TIC in future summers, you'd be well-advised to be more expansive in journal/weblog responses. One-sentence answers to questions that would benefit from more thoughtful replies won't cut it, to those who may recommend you for TAships in said future. (Not to mention to those who--well the 'one' who--does the hiring of said TAs.) ;p
p.s.: thread title ought to begin "Who's..." ;-)