Firstly, it's being filmed in 48fps, but I don't think anyone knows for sure whether it'll be distributed in 48fps. If there's enough resistance to the idea, it may show up as regular ol' 24fps. If it IS widely released in 48, though, it's hard to say exactly what the effect will be like, because hollywood has never really done a major, big budget movie in 48fps. Most of the stuff that's filmed in higher framerates is low budget stuff like soap operas, documentaries, and the like, which is why we associate the smoother motion with crappy video. However, it's worth keeping in mind that low budget productions are bad in a lot of other ways, too, which become incorporated into our perception of smooth video in general.

Anyway, lots of people definitely prefer 24fps, but the big question is whether there is a genuine advantage to the blurriness and chop that you get with that speed, or if it's just what people are used to. It's worth noting, though, that Roger Ebert has been pushing hard for 48fps, and Peter Jackson claims his entire crew prefers the new video.

I think it's safe to say that The Hobbit will look far better than any soap opera, but whether viewers can get used to the new framerate. . .*shrugs* It's an experiment at this point. Personally, I'm looking forward to it. Oh, and in conclusion, let me leave you with this (be sure to read the mouseover text): xkcd's opinion