I say this because even the best RBs last year will likely see a drop off this year in numbers, and they share more snaps with very capable counterparts. DeAngelo Williams and Michael Turner were (by far) the best backs in the NFL last year...fantasy-wise. But this year, Jonathan Stewart and Jerious Norwood will likely see a lot more time on the field. Even last year, Stewart scored as many TDs as Adrian Peterson...so he's got a great chance at getting in even more this year. Plus, he's a little bowling ball down in the red-zone. I really wouldn't be surprised to see him get more TDs than Williams in 2009.
The best RBs did stand out last year, but after them, the middle-of-the-road backs, fantasy-wise, really formed a big pack. I say, pick up a stud of a QB before getting into that RB pack. There will still be a few of them available in the second round of your draft. The best QBs will not!
Guys to take in the first round:
DeAngelo Williams - may see less time, but will still have a monster year
Adrian Peterson - as long as he stays healthy, he should have a better year
Michael Turner - not before pick #8. remember the curse!
Brandon Jacobs - late first round
Brian Westbrook - late first round
If you get the opportunity, definitely consider Drew Brees, Peyton Manning, or Tom Brady before any of these guys:
Marion Barber III
These guys make up the pack of great RBs, who all just seem to stick around the same fantasy-points league. I don't expect any of these guys to have a legendary season. Be safe. Pick them up after you've already got a good QB, or one of the other stud RBs.