For reference:
Randy Moss 2010 Season - All 5 TD's‏ - YouTube
As a fan, I want to see the Pats take a chance on him on a one-strike-you're-out type of deal, but if I was BB I wouldn't even bother. Moss still has the physical ability. I don't think that there's any evidence against this, aside from his performance last year, where there were clearly other things going on mentally that were causing problems.
A lot of people believe that Moss was bringing the offense down while he was here last year, primarily because of the Jet's game. The offense hardly struggled in the other two games Moss started though, scoring 38 points in both. Sure enough, after he left, the offense undeniably saw a temporary dip in production, culminating in a 14 point performance at Cleveland. That's the main reason that the fan in me wants to see him back; I don't agree that he was hurting the offense, and I think he could still be effective. However, the second half of the season was one of the most unbelievable offensive showings ever, and this is the reason that we DO NOT need Randy Moss, and we do not really need to sign any other receivers either!
Singing Moss would not significantly improve offense performance, and that's what we need to know. He might make a few spectacular plays, but those would be offset by the plays where Brady tries to force the ball to him, or where he is otherwise not useful. The offense might change, but it wouldn't appreciably improve.
That being said, I don't see the harm of bringing him to training camp if it's cheap (which it better be). But I'd prefer Sidney Rice.