I feel fortunate to have both Baker and Verlander on my Fantasy Team. I am in a keeper league that has 40 man rosters and keeps up to 20 players (max time you can keep someone is 3 years).
Right now, Baker will do better than Verlander. Next year they should be even, and 2 years Verlander will be better (barring injury).
Pitchers who have spent at least 1/2 a season in AAA with an ERA around 3.00 are ready to contribute, i.e. Baker, Duke, and Felix Hernandez.
Players called up from AA are to sparodic right now, i.e. Verlander, Ervin Santana.
That is not to say they can't succeed, but the chances are less. People called up from AA usually have a dominant fastball that AA players chase. When they get to AAA, they usually have a better pitch repetoire and are more ML ready.