Update 2: *Developing* 1.035SP (Sanyo 5400) may add MO-SMS…
Update: Contrary to some speculation, 1.117SP (Sanyo 8100) does not add SMS, nor RL.
Sprint is testing an update for the Sanyo 8100 (which, by the way, is about to be discontinued), version 1.117SP
Firmware update 1.034SP for the Sanyo 5400/RL2500 was rejected, Sprint is currently testing version 1.035SP
Sprint is already testing a new firmware update for the Toshiba/Audiovox 9950/VM4050, currently at version 132.038