Firstly, I would like to say I know that Move is a huge investment for Sony and you can't advertise functionality and remove it in a heartbeat.
So, how can Sony remove the USB function but retain PS-eye (needed for Move) functionality?
Quite simple actually!
1. If game requires move, then detect for Eye and see if it works (as you calibrate move, the PS3 KNOWS you're using Eye). Detect which port it's in, and disable use of other ports.
2. If game doesn't require move, disable use of USB ports as it boots.
3. PS3 firmware KNOWNS when it's charging a controller. Detect this, and ignore other ports.
4. This... Admitedly, will mean you can't: Import videos, Import Photos, or Export them either. BUT... I found KIND of a work-a-round... Detect for PSP! Stream via BlueTooth/Wireless access photos and videos! You could also do this STRAIGHT to PC.
So, question is : Do you even use your USB ports that much? Other than charging, and eye... Do you use it for conventional storage?