Unless this is a prelude to another trade (Vincent Jackson perhaps?) that nets the Pats a big-time WR, I don't see any way this can be spun as a deal that helps the team in 2010. This team is *not* better off without Moss.
Now, if they trade Mankins and a 2nd round pick to San Diego for VJax and, say, a 3rd round pick, then I'm ok with it. Mankins looks like he's not going to be much (any?) help this year, at least to the Pats, and adding VJax would give the Pats the WR help they just gave away, and for a longer period of time since he's many years younger than Moss.
But as of right now the WR corps is: Welker, Tate, Edelman, Slater, Price. Tate is ok, Edelman (if healthy) is pretty good, Slater is meh, Price...who knows? Only Welker is reliable out of that group. Losing Moss is a HUGE loss in terms of talent and depth. I'll be happy with this trade only if they turn around and make a deal for a different top-shelf WR.