Didn't you mean to say the current Windows 8 beta is faster? I hadn't heard that Win8 is released...
We'll see how things shake out when the final release ships.
Yes. The link I provided makes that clear. Plus it points out that even the drivers they are using have not been optimized for Windows 8 yet, plus Windows 8 code has still not been finalized yet, so they expect Windows 8 to be even faster when its finally released with proper Windows 8 drivers.