I was playing with 4X AA and I noticed when I walked, I'd get big white softened looking dots on the screen. Almost like flat snowballs. At first I thought it was environmental, it only happens when moving. It doesn't happen standing still or even turning. It seems worse during the day than night.
I googled it and it seems to be a common issue across many different Nvidia cards and this new game. The fix was to turn off AA, for some people setting the lighting to Bloom down from HDR fixed it. All I did was turn off AA and it's fine now. For some reason, the game looks better without AA for me, I am seeing sunrays, more specular lighting on rocks and stuff.
Such a weird and buggy engine. I had so many issues with Fallout 3, I'm surprised I was able to get through the whole game.
Overall though, I am loving this game. It seems easier though, tons of loot and stuff is dying quicker. I remember running backwards a lot in the first one.