Apple has released WWAN Support Update 1.0 which provides SW support for the following WWAN products:
Available on the Cingular network:
•Novatel Merlin XU870 ExpressCard (HSDPA)
Available on the Sprint network:
•Novatel Wireless Merlin EX720 Express Card (EVDO Rev. A)
•Novatel Wireless Ovation U720 USB Modem (USB Adapter, EVDO Rev. A)
Available on the Verizon network:
•Novatel XV620 ExpressCard (EVDO Rev. 0)
•Novatel V740 ExpressCard (EVDO Rev. A)
•Novatel Wireless Ovation U720 (USB Adapter, EVDO Rev. A)
More info and download link (350KB) here.
More about Macs and EVDO here.