Mine arrived this morning and I took a stab at it before I had to put it aside and get some work done.
Booted into Lion, ran boot camp, and rebooted to my sata dvd drive (win8 release preview dvd in the drive) using a usb/sata bridge. Booting with option pressed gave me a Windows option and an EFI BOOT option. Choosing the latter booted fine - looks like Apple has finally updated their uefi implementation!
However, Windows can only be installed to GPT disks when in efi mode, so I could not install it to the hybrid-MBR bungled mess the boot camp utility creates. So I fired up diskpart, cleaned the disk entirely and converted it to GPT. Ran through the first phase of setup fine, but once it reboots and boots from the SSD it bluescreens with IRQL_NOT_LESS_OR_EQUAL. And I was stuck - didn't even seem to be able to boot from the dvd anymore.
So I initiated internet based recovery and reinstalled Lion for now. Hoping to make a little time to play with it some more tonight.
My main concern is getting native AHCI functional, and UEFI boot is one way to do that.