Some awesome guy already made a visual comparison of the shot of the Enterprise from that trailer:

http://picasaweb.google.com/102542760950977079734/TNGHD

He points out that its the same shot, but recomposited from the original model that was shot on film. It's incredible work, what any good special edition should be: fix the composites and leave the rest alone. It's a shame they didn't have the original elements for TOS. The CGI is fun, just not MODELS.

What blows my mind is that they are going back to the original negatives, and re-editing the entire series from scratch. Every shot, every take, every effects shot, redone from the original negative. All of post-production for that series is being redone on modern equipment. I'm not a huge TNG fan, but I'm definitely interested in this.