One of the reasons that Virgin selected the Nexus 7, is that the slate can be updated on the fly, so to speak. Virgin's InFlight teammates took the tablets on a 30 day tests, and found that it helped them serve passengers better. The airline has started putting the Nexus 7 in the hands of its flight crew, and the complete rollout is not expected to take much longer.
Other airlines have given tablets to their pilots, to replace paper manuals, flight charts and maps. This actually saves the airlines hundreds of thousands of jet fuel annually. Besides the Apple iPad, the Microsoft Surface 2 has been approved by the FAA to replace pilots' flight bags.