I think this is a really cool idea! Especially for someone like myself who is decent at a lot of games but not great at any.

Maybe this would work better with smaller teams (two man teams?) and make it really casual as far as when to play your matches (kinda like scheduling your own matches on Madden).
I think Lord Geoff and myself might have a good shot at getting "Gold" in Galaga. Then again, we are some old-school gamers!
Edit: Or maybe we really open it up to any 360 game and have signups for all of them. Maybe only four people sign up for Tiger Woods, but that's cool. Heck, it's almost like everyone gets a medal for that event!