I'll actually be surprised if Lebron leaves Cleveland for NY, regardless of how much ESPN slobbers themselves over the possibility.
I mean, he's got it pretty good on the CAVS right now. He's a Cleveland guy to his core (grew up there, friends, family, comfort, etc) - it's home. They can pay him more over the rest of his career. He has already eclipsed the 'small market' advertising curse by becoming a huge international sports figure. Yeah, he might make some more on his endorsements in NY vs CLE, but is that worth the trade off? The CAVS have spent years building around his strengths and weaknesses - just like Jordan on the Bulls. He would have to start over in NY. Regardless of how good he is, building a true contender takes time - at least a few seasons.
Finally, I read somewhere he wants to be the first NBA billionaire and is friends with Warren Buffett. And Warren could tell him that you don't have to be in NY to be rich and famous.
I think he ends up like Tim Duncan and retires with the team that drafted him. I actually would be good with that. The whole east-coast dominated "if it ain't in NY or Boston it don't exist" thing gets old.
DWade, on the other hand, I think would be willing to go to Chicago, given how badly Miami rebuilt around him after the Shaq seasons. However, I don't know if he and Derrick Rose can share the ball enough.
I think NY lands one or two of Bosh/Amare/JJ with an outside shot at DWade.