I reloaded the game this morning and as soon as the game loads you can tell something is wrong - there's a flickering effect, the digital HUD graphics flicker and there's a weird oscillating shadowy blob that follows your vision every where.
I've reset graphic options to Low/Medium, restarted the game and rebooted my pc but to zero effect.
Here's a youtube video showing the flickering which I just uploaded: http://www.youtube.com/watch?v=9pHunEbDFy0
It's only 720p because I've lost my template for 1080p movies in Premiere but you can still make out most of the graphical weirdness - once youtube have finished processing the video, anyway.
My specs are:
Win7 x64 w/ SP1
Intel i7 920 @ 3.5Ghz per core
6GB of RAM
nVidia GTX 260's w/ 1.8GB RAM in dual-sli.