While I agree there COULD be a chance that Vick beats the "Dogkiller" Title but I think it is extremely unlikely.
Kobe has been a stand-up kinda guy after the charges were dismissed and Giambi has played well enough for people to forget his steroid use.
However, Dogs are mans best friend for a reason. Ever notice that people seem to get really upset when hearing about the "murder" of a dog and sometimes some people are more upset over a dog death than a human death? People of the world just flat out love dogs (not everyone but a think a big majority of us do).
So Vick will always be associated with killing dogs regardless of how well he does IF he comes back. (I really wouldn't be suprised if someone beat the crap and/or shot him after he got out of jail, again people LOVE dogs)