Can't say we're surprised, but AT&T has confirmed to us that the PlayStation Vita 3G will indeed be carrier-locked. Only Ma Bell's SIM cards will work; inserting a SIM from T-Mobile or an international carrier will not work. We spoke earlier with Glenn Lurie, AT&T's Embedded Device President, who estimated that the company first received Vita units for testing around four or five months ago and worked closely with Sony even before that on the 3G modules and connectivity rules in the SDK, which helps expedite certification and avoid apps that could potentially harm the network.
All that is detailed in the partnership agreement, the details of which we're of course not privy to. The North American PlayStation Vita box art for the 3G model highlights "Connected by AT&T" fairly prominently — and don't think otherwise. Plans start at $14.99 for 250MB and $25 for 2GB — same deal as iPad. So let's be clear: region-free, carrier-locked, and PSN-monogamous.