Is USB Apple’s Next Victim?. Andy Ihnatko on MacWorld:
So: no Ethernet, definitely no Firewire, and—in time, my pet, in due time—no USB ports. Apple’s answer to the inevitable outrage will be “If you must have that connector, buy it as a Thunderbolt dongle.
I can definitely see Thunderbolt being one of the only ports included on future Macbook Airs.