Yeah, I know; it’s a for-profit company and special receivers are required. But their very new Iridium Burst datacasting service could certainly fit the bill as an internim solution. I can’t find information on how much it really costs, though. It would be instructive to observe how well the service works in practice, and how they actually manage it.
Perhaps, the project could follow in Iridium’s wake and glide in the slipstream? People are always looking for an alternative.