I would hang onto Estrada, but Mauer isn't all hype. He is already a high average hitter, and is starting to show power already. That being said, I wouldn't give up much for him. He's still basically a prospect, albeit an extremely good one who plays at a very high level. Trade Clemens for IF/Util/RP help. Get rid of Cabrera. Why bother in a ten team league, unless he goes Brandon Webb all of a sudden?
Your starting pitching is very good, but I think your offense could use that one more big hitter to make a challenge for first.
Too bad the Braves aren't batting Girls second. That might put more butts in the seats.