Do these airlines with iPads use any form of moving map (like Jepp FD) with a bluetooth GPS?
I believe the airlines use it for charting only (ie as an EFB), but its been reported pretty widely. a couple of minutes search on AVWEB, or US AOPA or the FAA will probably get you all you ever wanted to know.
I hate the slothfulness of blanket statements such as "interferes with navigation instruments" What? How? Is this the mobile phone myth all over again? It took a properly conducted study in the British Medical Journal to debunk that for medical equipment, what does it take here? If Qantas really did a proper study and it found adverse effects, wouldn't it be unethical bordering on unconscionable not to share those results with the aviation community in order to improve safety? If the "Navigation Instruments"are really that susceptible to interference from Bluetooth, then there is a whole lot of other EMI in the big bad world that is potentially a bigger problem.
Lets just remember that the bulk of airliners flying are still pre-glass cockpits. Some are still pre-GPS. The navigation instruments on these rely mainly on gyro's & wires.