The big question for New Jersey is whether Dwight would prefer to play alongside Deron vs. Rondo + Granger.
My guess is this deal would only happen after Howard is traded elsewhere (such as LA). At which case, New Jersey might put Williams on the market.
With that said, there is no way they are trading Williams AND Lopez for two downgrades value-wise. Lopez, even with his faults, has much more value than Granger, even if its just for his contract, and Williams still has a lot more value than Rondo, if he goes to a team that thinks they can sign him.
With that said, you replace Granger with George, and I think this could be a very interesting deal for all teams involved.
I especially like Lopez for the C's, because he will have a cap hold of only about $7.5 million next season I believe. That gives the C's a little extra wiggle room to reload around him, before you sign him to a bigger longterm deal (which will be necessary...he is not signing anywhere for cheap).