I installed it before the Windows Update rollout as I wanted to test my own website. It seems to work fine and most CSS3 seems to be supported (unlike IE9). I have seen a small glitch with <header>s. A note for anyone occasionally writing CSS code: a number of CSS3 features, such as gradients, follow the final W3C standard which is different from the versions implemented as -o-, -moz-, -webkit- and earlier W3C specs. Most other browsers have also implemented these finalised versions - check the documentation.
2Mb/s? Not in my lifetime! (Nearly true Dec 2011)