...and surprisingly I think it's bloody ace.
I've installed it on a separate partition on my hard drive (just in case it turned out to be "Sail on the mayonnaise sea" (and yes, I did just type that out) before I bought it) and so far, apart from the odd glitch in the new "Metro" interface, I've found it really stable and dare I say it, even smoother than Windows 7 (I've updated my drivers fine).
It takes a bit of getting used to, like no start button for instance (you can install a 3rd-party add-on though...and it's good ). I like the whole look and feel of it. You can personalise the Metro interface to only show buttons to things you like and there are already lots of free apps on the store.
Anybody tried it yet? You can download it and install it direct from Microsoft here. This runs out in January but its good for a play to see if you like it before buying it when released.
At first I thought the new UI was a right royal pain in the arse but actually, now having used it a bit and having read the tips and tricks on the net, I really do like it.
(I type this using Chrome on Windows 8 8))