Wow, that was a bit of hassel but i'm finally there.
MacBook Pro retina with boot camp windows 8 RC fully working!
I've got Guild Wars 2 working nicely as well.
The reason it took a while... The laptop came with lion, not mountain lion... I had to go off to Apple, apply for mountain lion with my serial to get the free copy (that was quick) and then wait for it to download the whole OS.
Next I had to download Windows 8 RC and boot camp assistant took an ages as well download windows content for the install. Once into Windows 8, the boot camp install took a while and me being me, took a while to realise i needed to hold 'alt' when booting the machine to get the boot choices (I'm used to GRUB just appearing with Ubuntu)...
 Here is a quick screen grab one week in: