The only people who have made any real progress on running arbitary code on consoles are behind free software.
Michael Steil(sp) ? got linux on dbox2, gclinux etc part of the team with the jtag attack on 360 - no interest in copied software at all. Passed their findings to microsoft - says it all (and I agree)
Bunny with the old xbox - had no interest in copied software - more in running code on the box - passed his findings to microsoft.
Stuff running on certain 'cores' is one thing. But what about the first stage bootloader and the like you have actually on the CPU die?
I still stand by what I said, these people are interested in running homebrew, not backups. And the old fat PS3 does this on Linux. So they arent going to have the drive to do it.