The technology for the Aircraft, Satellite and Ground Segments has been around some years. The problem has primarily been regulatory (and still is). The same technology suite can be used for Mobile Voice and SMS Messaging (The FAA really don’t like the last two)
In Britain OFCOM have issued Guidelines and UK Airlines are planning, or reviewing introduction of these services.
Another problem is how to cost the service so that providers and the Airline Makes Money, so pricing is a real issue and a bit of a conundrum for all concerned.
Some consider that Mobile Voice and SMS costs per call will be easier for Passengers to swallow, rather than a big charge for total service link.
Others are avoiding the Mobile Phone issue and going only for internet connectivity, and therefore either charging by sector, or by time (Internet Cafe style).
In a decade’s time Unified Communication Access will probably be a standard feature, but for now there will be years of ‘Pick and Mix’ – Ranging from No Service through to Full Service and everything in between.