It is sooo hard to tell right now. First of all, the question of whether you should go for the best guy on the board, or biggest need. Then the question of whether or not it is worth the value, or if we get a better value by trading.
Even before those questions, much will change by the time the draft rolls around. Depends on who we sign/re-sign as free agents.
If we were drafting today and there were no trade offers, I think our biggest need is at linebacker, but the Patriots clearly prefer established veterans at the position and have not drafted a LB in the first 2, maybe 3, rounds. Think Vrabel, Colvin, A Thomas, Seau, C Brown, M Beisel, Pfifer, Cox and all the guys we've passed on in the draft under BB- Harris, Lawson, to name two. Same goes for cornerback, where they rarely draft high because (theory) they don't see a huge difference between the best guy out there and a third rounder.
I could see them going after a specialist guy, with Hester potential if available (Welker is a good returner, but lacks big play special teams potential.) We all know the value of a wild card like Kevin Faulk, who has a maximum of two good years left.
Also, they could go with another safety. This is a position where you need versatility and on-field leadership, and where there aren't that many great players out there. Along with Merriweather, they'd have two talented players with big potential. Harrison is getting older and Sanders is good but not great.
And although it sounds crazy, we all know how Belioli values tight ends. Watson is a free agent in two years, we've lost Graham, and we still don't have a stud TE that can change the game and add a new dimension to the passing game, and be a dominant blocker.
It is possible that we could draft a LB or CB, but we have yet to spend a high pick on either, despite having that need in the past. Belioli has historically tried to pickup veteran linebackers and grab CBs on the cheap, and these methods have worked.