You can tell they are getting GPU limited with the demo, due to the fact it's only 30fps and the AA method used. (However, it's still early days, but that's their framerate target anyway.)
Then, to make 30fps feel smoother, they added blurring techniques and this Demo has a bit of blurring on the objects and characters, not very pronounced in the video, but it is there.
If you look back at the Xbox 360 and PS3 launches, most games were in a similar situation, most running at 1080P initially, but when you start adding more effects and geometry, sacrifices had to be made and one of those eventually became the resolution after a few years into the consoles life, overall graphics did look better though, so it was a sacrifice that was well worth it from an overall perspective.
Man, I wish it would come to PC though, so we can dial-up the graphics, framerate and resolution more, with that said, I'm actually looking forward to getting my hands on a PS4, new uncharted trilogy perhaps?
Current gen games were never running at 1080p. Not even Resistance: Fall of Men.