Multibeast 5.0.2 for i5-3570k / ga-z77x-ud3h / hd4000
Mountain Lion installed very easily with Multibeast 5.0.2 for i5-3570k / ga-z77x-ud3h / hd4000
Only had to add the resolution to org.chameleon.boot.plist, otherwise the screen would come up scrambled after the 2nd reboot with a first-generation Apple Cinema display (22"), so just inserted this:
<key>Graphics Mode</key>
<string>1600x1024x32</string>
The Intel USB3.0 on the rear panel seems a little uncertain when connecting USB 3.0 devices -- it works for a Verbatim Store N Go V3 - USB 3.0 usb-stick but not with a Transcend TS-RDF8K USB 3.0 card reader.
As others have noted, USB connections seem to get lost upon waking from sleep (for example, usb-sticks give the error that they were not properly ejected).
eSata works, the added USB 3.0 ports from the Via VT800 chip don't (as it's not supported, but it's not a big deal since there are plenty of internal connectors for front panel USB headers), nor does the VIA sound (this was known ahead of time, but still chose this mainboard because it was the most affordable one I could get in Europe with a display port connector for resolutions higher than 1980 x 1024, extra power phases on the cpu supply, solid overclocking features, debugging led indicator etc.)