I wouldn't draft him in the top-5 of this year's rookie LBs, but after they are gone, then it comes down to players like Pollack, Burnett, and Cody or the later round MLBs and it really just depends on what your preference is at that point. Most people would rather have a starting SLB than a backup MLB.
The way Cincy will use Pollack should make him one of the few SLB's who have decent fantasy value. He'll be rushing the passer often and should put up 7-9 sacks along with 60 or so tackles. Consistency may ultimately be a problem but he is going to have his share of big games. I would agree with the Funk that Odell Thurman will ultimately make the better fantasy player in the long term. This is how I rank the rookie LB's for dynasty purposes
Odell Thurman MLB Cin - 2
Derrick Johnson KC - 1
Barrett Ruud MLB TB - 2
Lance Mitctell Ari - 5
Alfred Fincher NO - 3
Kirk Morrison MLB Oak - 3
Robert McCune Was - 5
Channing Crowder Mia - 3
David Pollack DE Cin - 1
If your looking for someone to contribute right away Pollack might fall in at #3 or so