Twins-it might be too easy to bash Joe Mauer here, and I was going to say avoid Michael Cuddyer until I took at a look at Mauer's Batted Ball stats. I don't see how he can repeat his phenomenal 2009 season. Mauer hit 28 HRs in 523 ABs. Nice power for a catcher, but he hit them while hitting only 29.5% of his batted balls in the air. And 20.4% of his flyballs resulted in HRs. Prior to 2009, here are Mauer's HR/FB rates-8.7%, 10.8&, 7.2%, and 6.5%. He also had a phenomenal .373 BABIP in 2009. I don''t see him duplicating his 2009 season, especially the power, unless he hits more flyballs in the new ballpark. This isn't to say he's not the top catcher, just saying I wouldn't draft him assuming a repeat of his 2009 season.
Tigers-I am not an AL guy for fantasy purposes, and rarely watch AL games, but what is the infatuation with Rick Porcello? I just checked his stats from 2009, and he didn't even strike out 5 batters per 9 innings. His FIP of 4.77 was almost a run higher than his 3.96 ERA, and he gives up more than a HR/9. Sure, he can improve in his second season in Detroit, but even his minor league numbers were similar to his rookie season in Detroit.
White Sox- I would avoid catcher A.J. Pierzynski and I wrote about him here. Catching prospect Tyler Flowers is close to being ready for the starting catching job in Chicago. Should Pierzynski get dealt, we don't know if it would be as a starter or as a backup.
Royals-if you were to chart Jose Guillen's HRs and BA since 2003, the trend would be similar to the S&P 500 over the last year and a half-not good. Here is his HR trend from 2003-31-27-24-9-23-20-9, and his BA trend-.311-.294-.283-.216-.290-.264-.242. Stay away.