Yeah, I didn't expect to actually get that clear of a look at Smaug before the movie was released. He looks great.
We still haven't seen a clear shot of Smaug, sorry, but it's just his head. We've not seen his neck, body itself with the jewels platting his underside and his wings and tail. To be honest, I'm not surprised we saw so "little" of him in the trailer.
As for the Trailer itself, it looks good, of course Jackson has changed a few things, especially the Barrels scene, but roll on the 13th December.