So I followed the instructions for oscdimg.exe and created SteamOS.iso. I'm on Windows 8 Pro, so I figured I'd try Hyper-V. I created the VM and chose the ISO as the DVD image, but nothing happens. Just get a black DOS window with blinking cursor. I mounted the ISO in the Windows Explorer (right-click it, open with Windows Explorer) and all the files and folders are there.

Here's the exact command I used to make the image:

B:\HyperV\SteamOS>oscdimg.exe -m -o -j2 -h -pEF -bB:\HyperV\SteamOS\SteamOS\boot\grub\efi.img -l SteamOS SteamOS.iso

Does it not work in Hyper-V?

UPDATE:

After a lot of futzing, I got it to boot the installer finally. It turns out that when you create the VM, you need to specify "Generation 2", which I guess enables booting from EFI. BUT, none of the Grub menu options work. :/

Guess I'll give VirtualBox a try.

UPDATE 2:

No go. Now I just get an "FSW ERROR" that flashes briefly then a GRUB shell. Oh well.