Some names that stick out as potential veteran UFA targets: Ryan Pickett (NT/DE), Tyler Brayton (DE), Chike Okeafor (OLB), Jason Taylor (OLB), Larry Foote (ILB), Keith Bullock (ILB), Kyle Vanden Bosch (rush DE), Casey Hampton (NT), Aubrayo Franklin (NT), Travis Kirschke (DE), Dwan Edwards (DE), Justin Bannan (NT/DE).
I'm not privy to the mental makeup of most of these guys, but all of them seem like they would be good complementary pieces in a young defense. The only exception would be Hampton or Franklin, who would be a Wilfork replacement.
I think it's a pretty safe bet the Pats won't be in the market for a safety. As long as they see Chung and/or McGowan as starting material for 2010, they are all set at the position, and will probably look to trade Sanders. Similarly, I don't see the Pats uprooting too much at CB; they will likely dump Springs, bring back Bodden, and keep developing Butler, Wilhite, and Wheatley.
On offense: Kevin Walter (big WR), L.J. Smith (TE), Nate Burleson (WR), Antonio Bryant (WR).
One RFA target that interests me is Owen Daniels. Supposed to be a smart, team guy, also very productive so far with the Texans. It would cost the Pats some to sign him, but it would be worth it for this offense.
The market seems pretty weak for OL this year. The Pats might be interested in re-upping Neal for one more year, and then moving on after that. I've liked what I've seen out of Connolly so far. There's also Ohrnberger, who has only seen the field a few times this season. Both of them I suppose could be options for the future, but if the Pats really wanted to soilidify the line they'd invest a high pick at OG.
Overall, the two most likely areas I think we see the Pats adding external free agents this year is receiver (WR and TE) and the front seven of the defense.