I seriously don't think any of the other players being mentioned hold a candle to what Javon has done.
Pennington - Yeah, after two serious shoulder injuries, almost everyone had written him off. And he's proven them wrong, but he's not exactly playing stellar ball. 9 TDs to 8 INTs is pretty pedestrian. A very solid case can be made for him just because of the seriousness of his injuries, but I think he'll have to pick up his play a bit before he garners serious consideration in my book. He's not really close to playing at the level he was at before his first shoulder injury.
DNabb - He was playing at a high level last season before his injury problems, but the organization went temporarily to shambles and they shut him down.
Rex Grossman - Certainly a case can be made for him, but as many have said, he never really showed anything prior to his injuries, so he's really just finally showing what he's capable of. Still, I think he warrants some consideration. I guess we'll have to see how he plays in the second half, but I anticipate a large dropoff in his production.
Kellen Winslow - See Grossman, comeback player suggests a returning to form of sorts, but his lack of a history doesn't give us much to go by. For all intents and purposes, this is his rookie year. I think his reputation as being an ####### won't help his case much, either (while I don't think this should be a factor, I think it will be).
Kitna - Going from Carson Palmer's backup to a solid QB doesn't really seem to fit the criteria for the award. And like Pennington, his 10 TD to 10 INT isn't exactly good.
Ahman Green - A case can be made for him certainly. Playing at a very high level, but not nearly as high a level as Walker. Walker IS what has made the Denver offense go all season long.
Deuce - Aside form his YPC, he really isn't doing anything more than he did last season prior to his injury, and his supporting cast this season is far superior. He's playing his role in that offense, but Brees is the main reason for the Saints success.
Brees - Played great last season. Had a week 17 injury, changed teams, and picked up where he left off. While not worthy of consideration for this award, I think he certainly warrants some MVP consideration.
Andre Johnson - Definitely a case can be made for him as well. He's played lights out. But most of this can be attributed to a new coach who has been able to get that offense somewhat on track. The addition of Moulds has also helped as defenses can't key entirely on him.
TO - He too was playing very well last season prior to his suspension. He has 6 drops on the season, at least two of which came at critical times and could very easily have cost Dallas those games. He has done arguably as much bad for that organization as good.
Kevin Jones - In my opinion, he definitely warrants consideration. He seems to have picked up where he left off in 2004. Much of this has to be attributed to the addition of Martz and Kitna (though the fact that he is fully healthy is also a big reason). With that passing game on track, he has had much more running room.
As for Walker, he tore his ACL in week 1 of 2005. Despite Marc suggesting that this is nothing more than a boo boo, it is actually an injury that can take some time to recover from. It baffles me that Marc writes it off entirey as nothing more than a minor setback. ACL injuries can significantly impact a player's speed and ability to make cuts (something that is integral to any WRs success). Furthermore, there is the mental aspect of getting back on the field after an injury of this nature without being tentative and holding back. This is obvious with Culpepper, who had almost as much time to recover as Javon did. Carson, too, was very tentative at first, and it's possible that this is still impacting his play somewhat. As I've said, there was clearly doubt among most as to whether he would return to his pre-injury form. Otherwise, Denver wuld not have been able to get him for only a 2nd round draft pick. Branch, who I think in most people's eyes is nowhere near the WR that Walker is, went for a first round pick. Chad Jackson, a WR who had never played a down in the NFL, went the pick after the pick that Denver traded. Santonio Holmes went in the first round. Walker, pre-injury, had established himself as elite, and thus would have warranted a mid first round draft pick or better if the consensus was that his injury was a mere boo boo and would not alter his ability to return to form. And, in spite of the doubt, Walker has already established himself as one of the game's best WRs, again. I won't bother posting his numbers, as that's already been done, but I suspect they will only improve in the second half now that Denver's offense seems to be back on track. I think 1400+ receiving yards and 12+ TDs is very much within reach. He is the most important player on Denver's offense, and a large reason that they are currently 6-2. I just don't see how any of the other players mentioned have "come back" from injury, poor play, or whatever, and so quickly re-established themselves among the game's elite while being so key to their respective team's success.
My 2 cents.