I must say some of the dwarves arent as I pictured them also. But we'll see
I figure the advantage of having so many dwarves in the movie, is that Jackson can't use each of them for comic relief, like he did with Gimli.
It's a Hollywood movie, it's meant to entertain the masses and generate a large amount of money, hence they will use the stylisic tools to do so. I find it too soon to judge on such things and more concerned about what goes into the film and what will not.