and I'm thinking that it would be awesome if there were an episode written by Steven Moffatt (does Doctor Who at the moment).
Please God no, Doctor Who is one of the most over-rated things on TV. The writing is simply awful and I can't believe that it's constantly praised as some of the best stuff on British television. If it was a tightly written show, I'd forgive the crappy acting, special effects and so forth, but the writing is probably the biggest offender so please, no, nowhere near my beloved Futurama or I'll cry.
I'd be interested to see any 'big name' writer's take on the show really, so long as it didn't become a common thing. Maybe one episode a season. It'd be nice for them to wheel out some of the all time great science fiction writers, or writers of the original series of Star Trek. Likewise, it'd be nice to see them wheel out some big name comedians. I don't really have a preference so long as we still get plenty of Ken Keeler, David X. Cohen, etc episodes.