It cannot be done at this time.
Most OS deployments must be done via local desktop manager, or WDM (web desktop manager).
Verizon, and some other carriers, are starting to do wireless OS updates on the carrier side starting with OS 4.5 and up. BES really doesn't get involved in this process other than being able to permit and request the OS update for the handheld. BES isn't pushing the update to the device.
See this thread for more detailed info: http://www.port3101.org/port-3101-be...device-os.html