I would be interested, so long as we can count on plenty of Planar wierdness, intrigue and so on. I, too, would hold up Shemmie's story hour as the perfect example of the kind of Planescape game I would want to play.
My preferred character choice would be a Fey'ri (demon-elf crossbreed), probably neutral and possibly a Cipher... or possibly a Taker... that's if you're allowing Faction affiliations for starting characters of course. If not that should still give a clue to his mindset.
I would advocate starting higher than 1st level, mostly because I would need to if I wanted to use that concept since Fey'ri have an ECL of +2 or +3. Ideally I would prefer to start somewhere between 5 and 10. If I'm outvoted, though, I can always knock together a different concept I'm sure... or, if you could stand the hassle, I'd even be interested in coming up with a short Savage Species-esque progression towards the full Fey'ri abilities.
EDIT: I counted three players already interested when I posted this. Doh. Still, if you'd be willing to go up to five my interest definitely stands. Otherwise I'd appreciate a place as an alternate.