when the technology has been installed which will allow us to actually make roaming calls onboard with our mobile....
The mobiles are not likely to be roaming to airtime provider sats on the ground but to be patched to Sat Comms installed in the aircraft, on request, via a prefix code provided by the crew (hence the airline making money from it - they provide the patching service, at a premium).
AOCs will have to consider all aspects of the impact of allowing mobile use in cruise before installing the technology. Privacy, volume, cost, benefits, safety and their competitors. It's going to cause one huge marketing nightmare!