I'll GM virtually anything if my players want me to. I'd certainly GM the "wrong" edition, though I vaguely prefer not to because frankly, every edition I've played of D&D has had something to recommend it and thus has been worth spending time on.
It's not just D&D of course, I kept playing 2nd Edition WoD when Revised was because Revised's main deal seemed to be "You guys are having WAY too much fun with this, it should be MUCH more upsetting!". I'm sorry guys, I like horror games like my horror movies. Post-modern, over-the-top and with more than a trace of humour (here's to you, Scream), not po-faced and depressing. That said, even Revised had things to recommend it, and I did run it eventually. Even the nWoD does, and my initial reaction to that was "So, even Revised was too racy, huh?".
Still, even I draw the line at Cyberpunk 3.0. A man has to have limits, right? My limit is using terrible scary action figures for art and having nearly completely incoherent setting.