A man missing off that list for me is Ahman Green. He's going to a system well known for running the ball (well, in Denver at least) and with a new QB, I think that will take the pressure off the running game and allow Green to have something of a comeback year.
The zone blocking scheme perfected by the Broncos and now in use in Houston could suit Green very well. He's only 30 yrs old and may have some life still left in those legs. After an injury plagued 2005 he came back last season to rush for 1000 yards on a pretty bad GB team last season. However, Houston isn't exactly known for its o-line prowess either. Ask David Carr's chiropractor. I wouldn't target Green as a #1 or #2 RB but he could make a fine #3 RB on your roster as a bye week fill in or maybe just maybe you'll get a steal if he returns to his 2003 form.