Carpenter should win the Cy Young. He won his 17th game today (and hit a grand slam!) with five shutout innings in his last tuneup before the playoffs.
His only real competion is The Franchise, who also won his final start today.
But Carpenter had a better year. Lincecum had a bad start to raise his ERA (2.48) above Carpenter's (2.24). ERA is more important than wins, but Carpenter also has a couple of more wins. Lincecum has an edge in complete games (4 to 3) and shutouts (2 to 1), but that's not enough.
Wainwright had more wins than both Carpenter and Lincecum, and he may get to 20 for the season, but his ERA will be high enough that he should be the third choice.