Before anyone complains about Vladimir Guerrero not winning, take a look at what he did and what Liriano did.
Liriano improved his ERA by over 2 runs between 2009 and 2010, and was probably better in 2010 than his ERA reflects.
Guerrero went from posting a .295/.334/.460 line in a pitcher's park to posting a .300/.345/.496 line in a hitter's park. He improved some, and played in 52 more games, but he still posted the third worst OPS of his career, behind only 2009 and his 90 game rookie season.
Liriano and Hudson are both deserving winners.