Michael Vick, Eagles
If not for a rib injury suffered in the first quarter of his team's loss to the Redskins on Sunday, Vick would certainly be on this list, and have a viable argument for its top spot. Since taking over for Kevin Kolb midway through the first game of the year, Vick has been a revelation for the Eagles. He has coupled his amazing athleticism and escapability with newfound acumen in the passing game, as evidenced by his 8-0 TD-INT ratio and stellar QB rating of 108.8.
Aaron Rodgers, Packers
A popular preseason pick for league MVP, Rodgers has endured many ups and downs in the young NFL season. Despite an exceptional QB rating of 96.3, he has thrown five interceptions already in 2010, just two shy of the number he threw all of last season.
Still, Rodgers has accounted for 940 yards and completed 69 percent of his throws, and generally has the Green Bay passing game running on all cylinders. If he cuts down on his turnovers (as he most undoubtedly will), Rodgers has the kind of ability and weapons at his disposal to be at the head of this list at season's end.
Matt Schaub, Texans
Having led the NFL in passing yards last season, opponents have been dropping back into coverage to contain Schaub's aerial attack. As a result, new starting RB Arian Foster leads the league in rushing heading into Week 5, which is why Schaub merits mention here. Still, he has put up gaudy statistics thus far in 2010, having already thrown for over 1,000 yards and compiling a QB rating of 95.6.