If Brett Favre has any more football left in him, he won't get a chance to prove it until the season finale in Detroit.
Per Pro Football Talk, the Vikings have made Favre inactive for this evening's game in Philadelphia. Favre still, as far as anyone knows, has not passed the first concussion test he would have need to pass in order to play this evening.
This means that Joe Webb will get the start at quarterback for the Vikings, with newly-signed Patrick Ramsey backing him up and even more newly-acquired Rhett Bomar serving as the emergency quarterback.