I would really like the Hobbit (unless they messed it up a lot or something) but I think that some people might not because the only people from LotR who are in it are Gandalf, Bilbo, and Elrond (and Arwen and Legolas if you wanted to make a stretch which I could see them doing). It would be really cool to see a movie of the Hobbit thoug.
I think the characterisation and voice of Smaug would make or break this project if they go for it.
Also Thorin. The ROTJ appendices make him out to be an amusingly flawed character- such a thing would have to come across.
Obviously, the mood would have to change- no-one would accept Trolls named Bert and Ernie, or whatever it was they were called... hardly the terror of the black speech, anyway.