OmniSky finally has a product page for its Springboard module. It is only compatible with the Visor Prism and Visor Platinum, but OmniSky is offering a $100 rebate for VDX owners that purchase a VPL or VPR between October 23 and January 31. There is a $50 rebate for New Prism or Platinum owners that didn't upgrade. Unfortunately the OmniSky service isn't in color at this time (grr).
There are multiple service plans that you can read about here. Buy early and you can get the OmniSky module for as little as $99. The module begins shipping in November.
I know some of you are disappointed that the OmniSky doesn't work with the VDX, but with a $100 rebate, now you have an excuse to upgrade.