I also believe Vasquez is an upgrade over Clemens, at this stage in their careers. I'm not a Yankee fan, but I certainly don't buy all the talk about their imminent demise. I would be a little concerned about not having a quality left-hander in the rotation, though, for potential match-up purposes in the post-season.
Not a big deal. Although Pettitte is a lefty, his pitching style (heavy on the cut fastball) actually makes him far more effective against righties than lefties -- which means he's a righty for all intents and purposes.