Just to be clear, I'm NOT advocating the Pats taking Ingram or any other RB in the first round in 2011. But, I can see how they might consider doing so. Maybe not this draft, but possibly in 2012 or 2013.
The fact that Brady stays as clean as he does has as at least as much to do with his special qualities as a QB (quick/accurate reads and releases, "sixth sense" about stepping away from pressure) as it does with the pass-pro abilities of the O-line. The strength of the O-line (collectively), in fact, seems to me slightly skewed toward run-blocking ability which, in combination with Brady's short game, is primarily why the RBBC has worked using guys like Taylor, Morris, LaMont Jordan and BGE. Nothing against these RBs, but - unlike Adrian Peterson - none are likely to get significant amounts of positive yardage without solid blocking help.
Looking ahead, Brady is getting older. The particular skills that make him great aren't the type that are likely to quickly/dramatically deteriorate, but it would probably be unwise to ignore the possibility that he'll diminish a bit, gradually, over the course of this contract and into his next one. It's also really unwise to assume that his successor will be anywhere near Brady's current level wrt quick read/release (at least not at first).
So, thinking ahead, the Pats might begin moving toward an O-line that is more skewed, talent-wise, toward pass-pro and away from run-blocking (for some O-line positions, at least). If so, they may, as a consequence, need to begin moving away from relying on average/older RBs and the RBBC system back toward more of a feature back setup and an RB (or two!) who can make significant positive yards on their own without a lot of blocking help from the O-line.
The odds of getting a guy like that (Peterson) in the first round are slim, but still generally far greater than in later rounds.
Now, ideally, yes, you'd want to acquire O-line guys who are very good at both run-blocking and pass-pro. If you look around the league, there ARE a few who are good at both - or, at least, had been for awhile at some point. But really, most O-line guys are usually good at one and not quite as good at the other and guys who are VERY good at both are extremely rare. IOW, odds are that there is a distinct choice involved for the team's coaches and player personnel guys.
Bottom line here wrt Ingram (or any other potential first round RB) is that BB is going to need to be damn certain that they guy is pretty close to being another Peterson before investing in him. It's still a much riskier proposition.
