People have been guessing this for the last couple of years, but I'm gonna say Anthony Randolph has a shot if he finally makes the leap people have been expecting him to make.
I don't really like the guy, but Andrea Bargnani has a shot at it if he can improve his defense at all and rebound a bit better. His scoring will undoubtedly go up, and the other stuff could conceivably happen if the Raps get smart and play him at the 4 instead of the 5.
Somebody on the Suns - I'm not sure who - seems like a decent bet. I wonder if Josh Childress has a shot at it, considering he wasn't actually in the league the last couple of years. I don't think Hakim Warrick is talented enough to have a high usage rate and still be efficient, but with Nash it's possible. Same for Robin Lopez.
Javale McGee, Andray Blatche, and Yi Jianlian are all possibilities as well given that they'll finally be playing with a point guard who can pass them the ball. One or two of those three is going to become the primary inside scorer for the Wiz. My guess would be Blatche. He showed late last year that it's possible for him to consistently put up around 15-20 pts and 8-10 rebounds a game (even though it doesn't usually translate to wins for his team).
Don't sleep on Nic Batum, either. The Blazers are expecting big things from him, and he should get even more playing time with Webster gone and Rudy in the dog-house. Unless the Blazers really think Wes Matthews is worth all that money and play him a bunch. But from what I've read the Blazers think Batum is a potential star, and will try to develop him accordingly.