Some good candidates:
Brady Quinn - Simple. Whenever he finally gets a chance to start, his value will rise. See: Aaron Rodgers.
Ray Rice - Could rise anywhere between 5-15 spots this season.
Rashard Mendenhall - Any first round rookie who flashes talent will rise up the boards.
Jonathan Stewart - Same story as Mendenhall.
DeAngelo Williams - Some risk, but has a chance to showcase his ability.
Chris Perry - If he's healthy, he might be the best RB they have. All it will take is a few good games for his value to soar.
Kevin Jones - I'll side with Borbely on this one. If he's healthy, he's the best back they have in Chicago.
Carnell Williams - High upside at a low cost. Could be an opening day starter in 2009.
Santonio Holmes - Value is already very high in shark circles, but will rise after he solidifies himself as a top 15 WR this year.
Sidney Rice - I think he's legit. It's only a matter of time until he's a perennial 1,000 yard WR.
Jerricho Cotchery - I see a big year in the cards for him.
Nate Burleson - Should have a big year and become a top 30 dynasty WR at least temporarily.
DeSean Jackson - I don't know if he has a huge upside, but he's probably going to have a strong rookie season.
Eddie Royal - Still ranked outside the top 60 dynasty WRs by most of the staff. I don't expect that to last.
Dustin Keller - Should gradually cement a spot as a top 10 dynasty TE.
Zach Miller - I don't think he's a great athlete, but the situation has converged to make him a top 10 TE right now.
Some of these guys carry a little more risk than others. I think the safest bets to rise in value are: Brady Quinn, Ray Rice, Sidney Rice, Nate Burleson, Jerricho Cotchery, DeSean Jackson, Eddie Royal, and Zach Miller. Mendenhall and Stewart will probably either rise a lot or sink a little. Santonio Holmes and Calvin Johnson will join the elite ranks, but many already rank them among the elite.