I had heard even before the mess with MGM got worse that the story started in Casino Royale was finished in Quantum of Solace. I think Craig even said in an interview there wasn't going to be a trilogy. I thought he also said he was hoping for the introduction of Q and Moneypenny.
It does seem like the right would be sold..though I swear I read somewhere that it would be unlikely that would happen if MGM went bankrupt or something... I think lawsuits were mentioned too. I think It might have been in one of my Entertainment Weekleys. I'll have to see if I still have it and what it does say. I think I did read a few different things about the situation, so I might be remembering stuff wrong.