Perry has little chance to be the starter in Cincinnati because of Rudi, but if he ever got the chance I think he would be a star on that team. Not only is Cincy becoming a bonfaide stud offense, (they've been knocking on the door for a couple seasons now) but Perry brings a couple elements to the RB attack that Rudi Johnson doesn't. He has has great pass catching ability and the explosive quickness to rack up big time total yardage(Parker[Perry] vs. Staley[Rudi]). Last year Rudi was good for 1400+ rushing and over 1500 total yards, Perry could make a run at 2,000 total yards if he had a full 16 games IMO.
I can't believe I just said that about a Michigan RB, but trust me he could still bust and then the world will still be right.
Gore is probably going to get more playing time than Perry barring injury, both short term and long term, but I still don't think the Niner's are at the point of recovery where you actually desire their backup RB. If you are in desperate need of someone emerging into a starting position so you can play them at some point this season, look no further than Gore.. I think he gets a chance to carry the rock over Barlow at some point, even without a Barlow injury.
If you want a legit sleeper candidate, I go with Perry and hope for an injury to Rudi.. (Rudi is a prime candidate for injury IMO - huge carry total last season, gets pounded regularly). If you are really desperate, I guess you can still start him because he is the 3rd down/passing situational/breather RB. He holds the "Kevin Faulk" role in the offense.
I picked up Ron Dayne off the waivers in a couple leagues last week, but I gave serious thought to getting Perry just in case because I have Rudi in both of those leagues. I think he is a great RB to stash on your bench... one of the most desirable backup RBs in the league and a must have handcuff if you have the bench space and Rudi on your team.