The phone function is slated (pun intended) to be removed for the US market.
The British O2 phone company is on the same frequencies, however as well as one of the Aussie telcoms. You could buy a GSM version from those markets and use an AT&T sim card.
Thanks, but I don’t understand that move at all.
If you want to one up or differentiate from IPad, make it a phone to!