I was a big fan of Spiller in 2010, and was interested in him for the Pats. Never expected him to go #10 overall, which was a big reach. I think he would be a terrific weapon, but I'm not sure what his market value will be. I'd take him over Vereen, but I wouldn't break the bank, and I don't think BB is willing to spend on any RB.
Another guy I like is Knowshon Moreno. I wanted the Pats to sign him last year in FA. I thought he would be a starting caliber back with receiving skills who would add a dimension to the offense. Moreno, like Spiller was a high draft choice who didn't live up to his draft status, and who had one really good year, but who has an intriguing skill set. He signed a 1 year/$3M contract with Miami, so not huge money, and then tore his ACL. He'll probably hit the market (especially with the emergence of Lamar Miller), and won't command much coming off of an injury:
The guy who I'd actually like to make a run at if the RB market is soft is Ryan Mathews, a bigger back than Spiller and with terrific receiving and blocking skills. Like Spiller and Moreno, a high 1st round pick (taken 2 picks after Spiller in the 2010 draft), fairly young, and with a career marked by inconsistency and injuries. Still another former high draft pick who never lived up to it is Darren McFadden.
I think any of these guys would be good paired with Blount and the others in a RBBC. I'd address other needs first, see what the market is like, and potentially snag one if the value is there and the money available, but I wouldn't make it a priority over a starting caliber guard. I'm guessing that with so many of these guys available that the market will be soft.
There are early reports that DeMarco Murray will hit FA this season. Des Bryant and Murray are both FAs, and the Cowboys will be hard pressed to re-sign both. They've apparently made it clear that they are willing to spend big for keep Bryant, but they have reportedly low-balled Murray with a 4 year/$16M offer that isn't going to get them anywhere. Reports yesterday was that he will likely be allowed to leave in FA, with the Cowboys confident in their OL and a draft stacked at RB to fill the void.
ESPN's Matt Williamson discussed 7 teams that could potentially make a run at Murray. #7 on his list:
7. New England Patriots
Shane Vereen and Stevan Ridley are free agents and might not be back. Meanwhile, the Patriots just opened up a ton of cap space by reworking Tom Brady's contract, though much of that could go to Darrelle Revis. LeGarrette Blount will return to the team next season, and he currently sits atop New England's running back depth chart, but he isn't nearly the player Murray is. It could be the point in Brady's career -- though he is still playing at a very high level -- to take some burden off his shoulders. A running game led by Murray would have the potential to do exactly that, especially if the Patriots can add some interior offensive line help. Bill Belichick and Brady might not have a lot of years left together -- why not go all-in with an aggressive move such as this?
Seems like a very long shot to me (and probably why the Pats were the last team listed), and we've seen how "all in" worked out for the Broncos, but something to think about.