AT&T has now confirmed what many people had probably been suspecting all along: use of the American 3G Vita is indeed locked to one carrier. Whereas the Australian version allows people to buy SIM cards from any carrier they feel like, insert, and use as they will, players in the United States have AT&T as the singular option.
Wonder arose by those curious about what would happen if someone put in a SIM card from an international wireless data service provider such as T-Mobile. Could the American Vita still connect via 3G? Now we know that it can’t, similar to how the Japanese device will only recognize DoCoMo cards.
The results of bringing a foreign Vita into North America with a SIM from an international carrier have yet to be seen, though even if that works, the inconvenient processes of purchasing and importing will put off a lot of customers who might otherwise be interested.
[Source]
