I also think that there may be a fine line between preparing ourselves for a future need (assuming the loss of Talib, and/or injuries) by selecting a developmental CB, and potentially wasting a roster spot by going after a player who will cost a couple/few million dollars this season.
In other words--do we need another CB? Of course we do, but that CB may also be chosen via the usual routes of lower depth chart signings in a veteran or even a mid to late round pick.
We have starters at the moment in Talib, Dennard, Arrington, and possibly even Dowling--since we have to certainly include him in the mix and can't keep complaining about an injured player. That gives us 4 at the moment, with the possibility of having McCourty either move back permanently, or rotate back and forth like we saw in SB46. Either way you look at it, we definitely have at least 4-5 starters right now. I don't see anything more than some usual depth competition and or a developmental choice in the draft. It's my belief that a good argument could be made for wasting too much money and resources on this position, with other positions needing attending to.
However, no one can answer that question unless they knew what Belichick's personal thoughts were regarding a number of variables. He may surprise me and select someone in the top 2 rounds, but I'm expecting something in the mid/later round range myself.
A vet like Sheldon Brown or Antonine Winfield would be great, but probably wouldn't see much, if any playing time, and really wouldn't justify the cost. I'm assuming the same came into play when considering players such as Asomugah etc, who came relatively cheap. Grimes probably comes into a totally different category altogether, due to market cost and injury concen.