I have a Mac Pro 2009 and I intend to keep on OSX 10.9 Mavericks for the long term. I study the possibility of installing an IoScale 3.2TB for storing video and photo footage, but I would love to get a bootable disk.No, you can't boot from it w/o a TON of UEFI hackery that I haven't had time to look into.
Currently, there is a very interesting project called OpenCore It simulates EFI loading before the system boot, offering the possibility to load drivers (kexts), such as video boot for graphics cards.
I think it would be the ideal environment for hack work that aquacow cited as necessary to be able to boot from Fusion disks. Any idea which path would be needed?