Long-time 49ers fan and football afficianado here: and Vick's a tricky case.
It's not that I don't think he shouldn't be allowed to play again. What he did was heinous and inexcusable, but then again he did do his time. He broke the law- what makes Vick tricky is he didn't just break a legal law- he broke a moral one.
(Granted, I'm somewhat of a Hobbesian, and I don't really believe in innate moral laws and human anture, but that's being left by the wayside here.)
So he did his time, and, legally, he's clear. Morally (supposing, again, for the moment there is a moral law at all) he is still guilty. However, our legal system is based on what is lawful, and not always what is moral, and that is for the best; if we had a fixed moral standard, then... you know what, I'm really not going to get into this philosophical debate.
So Vick legally is clear, morally is irrelevant- and I think he should be allowed to retry his career path.
And THAT I think is what sticks in folks' craws a bit (mine included, to an extent.)
If Vick were a bricklayer by trade, and wanted to come back to his job, this would not be an issue. But he's a football player, which is a profession that garners millions; what's more he's a quarterback, and quaterbacks are both symbols of their team (so what does it say when your QB is a convicted felon?) and paid even more than most other players.
Again, if Vick were a bricklayer, no problem. But he's a QB, a figurehead of a franchise and a multi-million-dollar man, and folks don't think he should get all that again.
Me?
Vick should be allowed to play; morality aside, again, if he were a bricklayer he'd be allowed back, and the public would think little of it. He's an entertainer, and qualified for his position (you can debate his merits in different areas, but overall it's agreed he was an exciting player.) It's the fact that he's being allowed that money again that bothers me. The fame and notoriety- again, I don't think morals should be the subject here, especially as Vick's an entertainer, and not a world leader; a poor role model yes, but entertainers don't have to be good ones.
It's the money that bothers me- money is power, after all, and the notion of giving a convicted felon that power "back" seems logically irrational, it's essentially supplying him with the means to commit his crime again, should he choose to.
Vick should be allowed to play, but I think that his wage should be somewhat garnished and given to humane societies as further payment for his prior actions, and obviously he should be under close watch and supervision in his on and (to an exent) off the field actions by the NFL