Excellent update. I've been using the nightly builds daily at work, and they've steadily added more features between b1 and b2. It's stable as a rock, as well.
The textures included with this beta demo aren't of the highest quality, in order to keep the file size down to 740mb instead of a couple of gigabytes. Still, it looks great and I get a steady 60FPS with my C2D E6320 (OC'd to 3.2GHz) and 8800 GTS...
Read full review
This is a nightmare to customise. Not only do you have to hunt around for multiple files in order to get your foobar looking half decent, but you even need specific versions of plug-ins for some skins to work.