If you guys watch a HD quality of the trailer very carefully you can see the beginning models and textures are VERY DIFFERENT from the in game footage.
For example the first 10 seconds, the models looks VERY crisp and as promising as last year's trailer. However if watch a bit further into it, it quickly degrades. Look at the platform the people are standing on. At first glance when it is seen, you can see clear lines marking vents on the top of the ship and what not. 10 Seconds further into the trailer the texture of the ship quickly becomes blurry lines, the models lose alot of their definitive features it had from the beginning...
I personally believe they mashed up some CG work and some in game footage into one trailer, either that or they have already found the PS3s limits.
If you dont want to go and download the HD quality of the trailer, simply goto GameTrailers.com. You can view it there. I personally like using Quicktime because it downloads the video rather than it streaming the video.