Take a look at Tom Brady's stats for his six full seasons in the NFL.
That is amazingly - almost unbelievably -- consistent. The one year that stands out is 2005, when he shot up to a career high in passing yards. That was due to the running game though; Corey Dillon only started ten games and the Pats were forced to utilize Patrick Pass and Heath Evans at RB. Their team rushing yardage dropped a whopping 29% from the year before.
Through several running backs, through the rise and fall of Deion Branch, through about a dozen tight ends, Tom Brady keeps putting up the same stats. Why? Because that's the way Bill Belichick likes it dammit! The Pats run their offense like a well-oiled machine and as long as all the pieces are playing, the offense will continue to run.
Will the addition of Randy Moss change that? I say it won't. Even if the Pats were getting vintage Randy Moss I don't think that they change what's been working. Considering they're getting a physically and perhaps mentally banged up Randy Moss, they're definitely not going to change. Sure, we'll see more long passes and Brady's yardage totals may tick up a bit from last year, but I don't think there's anyway he gets close to the 4110 yards he put up in 2005. If you're drafting Brady thinking he's going to put up 4000+ passing yards, I think you're buying into the hype.