I know it has been done with the Air though can it be done with the Pro and Mini and at what cost. Would Apple do it for thinness?
I hope not, I use the ethernet port. wifi's bandwidth comes no where near the speeds of gigabit ethernet.
Except that USB is is 400mbps (peak) and usually 1/3 of the sustained while Gigabit Ethernet is 1000mbps sustained sure...
I could see them make it a thunderbolt dongle though in the future for the non-pro models.