I agree with the notion that Webber simply hasn't been a good player at all since he has left the Kings--the fact that he's been the worst defender at his position (I could be wrong about this, but I remember a sixers fan quoting this elsewhere awhile ago) really means he's much more of a drag on his team than an asset. It's not his fault that he's basically playing no defense right now, 'cause its' just really unlucky that his knee basically takes away any hops and mobility he had, and well, it's really hard to play defense when you can't move laterally to keep up with a defender.
I think it's still very hard for a lot of us, emotionally, to let the Webber trade go--he was a big part of the turnaround of this team, just like J-Will and Vlade, but rationally, it's hard to see what the Kings have given up basketball-wise. I think that people who're saying how the kings aren't as good now as they were before are missing the point--the entire team's different--the wear and tear that comes along with age has just caught up with the Kings. Christie and Vlade are now out of the league, and Peja has gotten injured with greater and greater frequency nowadays. I don't think we can just jump to the conclusion that Webber is a negative influence just because the Kings had the best record in the league when he was injured and was a .500 team when he came back, and for the same reason, I don't think we can jump to the conclusion that Webber was the reason why the Kings haven't been as good as they were before since the trade.
I think that rationally, what the Kings gave up was one giant bloated contract for 3 smaller bloated contracts. The hope was that the smaller ones would have been easier to move, but it turns out that it really wasn't much better--the only one the Kings could move was the least bloated one, Skinner. The Maloof's actually did save a little bit of money from the Skinner trade, but ultimately, the Kings got very little out of it financially. And basketball-wise, the Kings gave up very little, but didn't get very much in return either.
Of course, emotionally, that trade, along with the Christie and Peja trades and the departure of Vlade, signalled the end of the Princeton era, an era with its highs and lows, the excitement of the most brilliant basketball played in the NBA at the time, and the repeated disappointments of coming so close and failing to get the ultimate prize.