I like this deal for everyone but the Red Sox to be honest. Huff is a nice bat but he's no Manny Ramirez. If I were Boston, I'd look to trade Manny, but not now. I'd try to move him in the offseason, where you could sign a big bat to replace him. It's hard to get rid of a force like that in the middle of a pennant race.
Mets get a huge, HUGE bat in this deal, as well as a very solid reliever. Tampa probably would get several very good prospects like Milledge, Petit and others from Boston.
I don't know what Boston is thinking with this deal. Trading Manny makes sense to me, but not unless they are able to replace him, and that probably isn't possible in-season. It's better to trade him in the offseason, and use his money to get some top-end free agent bats.