He may not be the best RB in the NFL yet, because he is not a great pass catcher or blocker... but I think that Adrian Peterson is already the most explosive RB in the NFL with the ball in his hands.
He single-handedly won it for the Vikings today (with a little help from Ryan Longwell). 20 carries for 224 yards and 3 TD. He also set up the game-winning FG with a long kick return. For the game, he had nearly 360 total yards on 25 touches (20 carries, 1 reception, 4 kick returns). Wow.
Through 5 games he now has 607 yards rushing, 4 TD, and 6.3 YPC. He's also got 10 receptions for 175 yards and a receiving TD. For good measure he also has 248 yards return yards. So by my calculations, through 5 career games, Adrian Peterson has 1030 total yards.
This is why I thought Adrian Peterson would be the Rookie of the Year.