I don't understand what you're trying to say, and I doubt you understood what I was saying. I was not saying get rid of USB for data transfer, but make it built in, and OS independant. That way you could plug a standard/normal mini-B USB cable into a USB, and plug it into any PC running any OS, or a 360/PS3, and it shows up as a standard USB harddrive.
It's debatable whether the UMPC hard drive should appear as a USB drive on another PC. If the other PC attempts to boot from the USB drive, that will seriously scramble Windows.
It would do no damage to the PC trying to boot from the UMPC.
And Windows on the UMPC would simply crash, since XP won't boot off on a system dissimilar to the one it was installed on.
So unless both PCs were the same kind of UMPC, the boot would simply fail, with no damage, except a loss of hibernation data if it existed