To be honest, and maybe I'm just telling myself this so I feel better, I don't think the 31 pick could've been used to help the OL that much. Tackles were going like crazy in the first round, and I think everybody we'd be interested was gone by then - and then the guards that seemed like good fits didn't start going until round 3. We could've taken one of those guys and they didn't, so that means they must have faith in Britt and or Yates and or O'Cal.
As for the OL - I was reading a season preview the other day, and they had a brief scouting report from an opposing coach for each team. For the Pats, the main point was that "Brady makes the offensive line look better than it is". I and some others echoed these thoughts in a thread recently to some criticism, but coming from an NFL coach, it has to be taken seriously.
I think its accurate - as long as Brady is there, and now especially w Moss and Welker, he can take a fairly solid line and make it great. Bottom line, the OL will probably be OK no matter who they plug in.