Tested in:
7955 Leak
7989 Leak
Developer Preview
Consumer Preview
RTM (9200)

And it seems osu! actually obeys the FPS limit too. Before, osu! would run at a reported 130-140 FPS when my cap was 120 FPS, but it sticks at 120 FPS now on Windows 8.

Heh, I thought my GPU driver was broken or something when I saw that at first :p

slightly painful to watch, I must say..

Define: "Works."

Runs just fine, no issues whatsoever. I think the only thing you have to do is enable the .NET 2.0 and 3.0 combined package from Windows Programs and Features, but other then that, osu! installs and works without any compatibility settings needed.

One thing I noticed.. text seems crisper maybe? In any case, text is different... (Softening filter is disabled)

Eugh, text looks uglier and way more aliased.

Now that you mention that, it does seem like the text has a look similar to when MLAA is enabled.

I'm using AMD's 2/29th WCP Drivers currently, and the MLAA option is disabled also

Yes, I concur. osu! works just fine on Windows 8 consumer preview. Running it now and no issues whatsoever.

Works fine on Win8 RTM (9200 Enterprise x64) as well Had some strange .NET issue earlier though that caused osu! to crash on startup, but a quick reinstall of the .NET 3.0/2.0 package fixed it.

Also works alright in Windows 7.

How did you find out?

Oh man, that's awesome! I've been hesitant all this time because I wasn't sure if it'd work, thanks a lot for this super useful fact!

I can confirm it works on calculators.

....what? Made my maths lessons more entertaining...