Vick is more or less finished. The commissioner is still planning on suspending him, regardless of the public relations crap coming out of his office, and now his two remaining co-defendants are pleading guilty. Must be nice to have such quality friends.
So with Purnell Peace and Quanis Phillips leaving Vick out to dry, we move on to the decision making portion of this. If he tries to cut a deal at this point, Vick has no legs left to stand on. His fellow defendants have almost certainly incriminated him further, but he's got nowhere to go. If he pleads guilty, he's automatically out of the NFL, he's probably off the Falcons for good, and he'll probably at least face some jail time. If he keeps fighting the case, there's a pretty good chance he'll lose it and have all those things happen and then some. For all intents and purposes, this marks the end of the Vick saga in the NFL. He may battle through this and come back someday, but that will be a new story with a fresh twist. This has just become the tired and sad story of man whose money and interests got him in way over his head. By next month there will be another one somewhere in the public eye, and Vick won't matter much to most people anymore. PETA will have new signs for someone else, at the very least.
Personally, I'd think Vick has to at least try to cut a deal at this point. I can't imagine Peace and Phillips managed to cut deals without leveling the legal shotgun at him. The only chance he stands of ever getting out of this mess is just swallowing his pride and dealing with the consequences. If he really is innocent or thinks he is, he'll probably continue to fight the charges. With every day bringing news about how little help he has, he's now facing two more charges by Friday if he doesn't change his plea. Mike Vick's endorsement deals aren't coming back after this one. Hell, his life probably is never going to be close to the same as it once was.
So Vick needs to repress the urge to freelance and spin away from his attackers like he's always done on the field. Sometimes the best and only play is the one where you end up taking the hit. Whether Vick takes that hit--and gets back up off the turf--is up to him. With everyone but his legal team abandoning him now, hopefully he has the sense to do what makes sense for him.