Williams is playing well, but just from what I've seen mostly from the three Pistons games in two weeks or whatever it was, plus a few minutes of a couple other games like tonight, and it's just my impression but people on GAF and elsewhere have the same one for whatever that's worth, is that he's basically just going out there, doing what he can do and if the game is close he'll step it up but otherwise is content to list along accepting the losses.
You could tell in the Pistons games, he'd get hot and make some good baskets and yet he'd look as bored and dead as the rest of the Nets. When he started going crazy with the threes was the only time anybody on the team seemed to perk up and he still didn't seem entirely invested, like "yeah, yeah, I'm awesome, but this isn't going to mean anything." And even when he wasn't making shots but was with a lineup he liked running with he was pushing it more, willing to try lobs and stuff, but other lineups he was content to just pass it off and let guys get their numbers in defeats.
I think it's really just a factor of how much of a mess the team is. They're 10-24, he steps up and plays as hard as he could all season long would they really be any better than say 14-20? Johnson is still dicking around with lineups as well considering all the injuries they have. From the Pistons games Deron seemed to like being with the younger guys than the DeShawn Stevensons and was a bit more active in trying to get them baskets. But that could be entirely out of curiosity.
Regarding the Lin stuff, it's worth noting that Williams has been asked a ton about Lin because of it "starting" with him to the point a few days ago he basically told reporters to STFU about it as he got a bundle of questions about Lin and none about his game or the Nets. I could understand him saying "I'm tired of talking about this and I'm going to wreck them so it goes away."