I have mixed feelings about the deal.
One I believe Lackey is a injury risk. He's had arm issues the last couple seasons and couldn't break 92MPH vs the Yankees. Which isn't a big deal, but he is supposedly a power pitcher.
2, I think this may lead to a Buchholz trade. Which I'm very much against. If they keep Buchholz and go with the 5 man rotation of Lester, Beckett, Lackey, Dice-K, Buchholz I think it would be better the trading him off for Adrian and creating a whole in the rotation.
3, if they trade Buchholz they have a hole in the rotation to fill. That may not sound big now, but if Beckett leaves next off season the Sox will be left with Lester, Lackey, Dice-K, not exactly great, but not horrible.
Beckett is going to want a similar deal or more IMO. I would have rathered they gave the money to him, but if they are willing to extend him too then I could really get on board for this deal. But if Lackey is coming into replace Beckett/Buchholz, I'm not sold.
But like I have always said, I'll support however they throw out there.