I think Backe is going to be just fine, I could see him going 6-10 over .500 in games he starts.
If we can get .500 from all guys not named Pettite and Oswalt it seems like we could reasonably expect to win 90 again if Roy and Andy don't miss turns. Is 90 enough to win a wild card (or maybe division if the Turds crater?) I think it might be.