Losing weight and gaining quickness like he did made him a much better all around back. Also, playing in an offense where he had a chance to catch a few passes didn't hurt either.
Last year I would've said he'd probably make a team in the NFL and have a brief career as a back up. This year, I think he's got potential to be a high draft pick and be part of some team's 2 back rotation, since that's what most teams do these days.