It's a tricky thing to predict how Andy Pettitte is going to pitch after a year off, and that's assuming that he'll pitch at all for the New York Yankees. But Dan Szymborski dusted off his abacus and took a shot at a ZiPS projection. The conclusion:
I asked the ZiPS projection system (which contains data of pitchers who have missed time throughout history) to project Pettitte for 2012 and it puts him at ... a solid, league-average performance. (His projected) ERA is better than the 4.85 and 4.84 ERAs projected for Freddy Garcia and Phil Hughes respectively.
It's an ESPN Insider piece, so I didn't want to give the entire projection away, but it's as good as guess as we have to go on, and it sounds about right. Looking for Cy Young votes? That's a few years in the past. But looking for league-average innings from the fifth or sixth starter on your staff? Pettitte is probably a good bet.