The joy on Schumi's face after the race explains why he's still in F1. I'm sure he'll continue to be here as long as he feels he can win, or as long as he's fit. I think it'll be the former more than the latter and as it is right now, I don't see him getting "tired" of winning at all. In fact, I guess 2005 was just the kind of break he needed...a year with one win to get his zest back for this season. Excellent.
This season is really starting to get all exciting now. Go Ferrari!!