My vote is for "slight distraction", just because he can't help himself. But I think it'll be far less than anticipated, and he'll help greatly.
Right now he's saying all the right things. "I didn't do this for the money". "I'm the second-best WR to come out of Marshall next to Troy Brown." "This is a great opportunity." Et cetera. And I think he means it, for the most part. He's old enough to realize his time is running short, and his abilities are starting to decline, and he WANTS to win. Much like Corey Dillon, I think we'll find that winning cures all ills.
Also, don't underestimate the Doug Gabriel factor. Supposedly, Moss and Gabriel were good friends. The Pats got Gabriel. He supposedly was late for meetings, wasn't giving 100%, couldn't grasp the plays, whatever. The Pats cut him loose. Now, some people might think it's a BAD thing that he and Moss are buddies, because they think Moss will come in with the same attitude; on the contrary, I think it's a GREAT thing, because I'm sure Moss now knows, via Gabriel, that the Pats will not #&*% around. Moss knows that if he screws up he's gone, and his career and reputation go down the tubes once and for all.
The best thing Moss could've done was restructure that contract. It shows good faith on his part, that he's coming here to win. If he came in with a huge contract, I think the fans would be very hard on him; but coming in with such a small contract, I think the fans will be very appreciative of that and will cheer and support Moss to a large degree and that it will surprise a lot of people.