They have barely started the optimization phase. Apparently they disabled quite some eyecandy features to get stable fps for the presentations, since the game isn't optimized yet. You can see that many screenshots they released (and also the footage from VGX and SoD trailers) look considerably better, so they have these eyecandy features in place, they're just not optimized enough yet.
I didnt know we already had this information. I remember some discusion a few months ago. Finally i was right. This are not the graphics i saw in SoD but your explanation has totally sense. Thanks!