The artists he has on board are responsible for some of the best depictions of Smaug (and Middle Earth art in general) ever. I doubt it'll be screwed up.
Not like the animated version, at least. Sheesh... western dragons shouldn't have dog noses. (Personal preference)
Speaking of dragons, here's a morbidly amusing picture:
Agree, the Bakshi version just didn't do it. Miore cool stuff here:
http://www.tumblr.com/tagged/smaug?before=1324689762Dragons may not have much real use for all their wealth, but they know it to an ounce as a rule, especially after long possession; and Smaug was no exception. He stirred and stretched forth his neck to sniff. Then he missed the cup!
Thieves! Fire! Murder! Such a thing had not happened since first he came to the Mountain! His rage passes description — the sort of rage that is only seen when rich folk that have more than they can enjoy suddenly lose something that they have long had but have never before used or wanted. His fire belched forth, the hall smoked, he shook the mountain-roots. He thrust his head in vain at the little hole, and then coiling his length together, roaring like thunder underground, he sped from his deep lair through its great door, out into the huge passages of the mountain-palace and up towards the Front Gate.
J.R.R. Tolkien, The Hobbit
Personally, I can't wait to see the 3 Trolls scene ("Mutton yesterday, mutton today, and blimey, if it don't look like mutton again tomorrer," said one of the trolls.). Hopefully these will look like real trolls, not those shown on LOTR. From IMDB, it looks like one of the lucky actors playing one of the dwarves has a dual role in playing Tom the Troll. Reading that scene was the first time I descended from normal kid books to 'grown up stories' when I was ten or so.