Sony Ericsson today quietly added the Z310a to their American portfolio. Though not yet available on any carrier, the Z310a is the non-Walkman cousin of the W300i. While it is possible that the Z310a is simply to be released on unlocked and unofficial channels, it is also possible T-Mobile may carry the device. T-Mobile has not sold a Sony Ericsson device since the T610 in 2003.
The Z310a does not have a launch date yet, though it is expected to be released in the United States later this quarter.