Unloading Abreu was a good thing as it freed up money, plus the guy doesn't play hard every day. His power disappeared and I think he's on the downside of a very nice career.
I disagree about Abreu, at least in the extent of time I've seen him in a Yankees uniform. He's been great at the plate, with an amazing OBP, and I think part of the power problems he's had were with the fact that he was pressured to produce for a lineup that lacked big swing power. I think he should get a bit of his stroke back, I'd say at least another 5-10 dingers, with that short porch in right field in Yankee Stadium this year.
And I haven't seen any of the "slacking" which characterized him in Philly...as far as I'm concerned, he's a 100% defensive improvement over Sheffield. Offensively...if A-Rod can come back strong this year, and Matsui will get back from injury, and Giambi plays well at first, Abreu's OBP should help out tremendously even without Sheff's cannon line drive homers.