Personal electronics might cause interference with airplane avionics, but there's seemingly no proof: For unknown reasons, the New York Times trots out a story that could have been written at nearly any point in the last five years about the potential for personal electronics to interact with avionics (airplane electronics and control systems) to deleterious effect.
I've followed this story for years, and there's no new information in this piece. Over a decade, the only association of passenger gear and cockpit trouble is from "at least 10" reports by pilots in the United States, all of which are anecdotal, and, ostensibly, none of which have proven repeatable. If they were repeatable, we'd have different restrictions and rules, instead of ever-fewer ones.
The article notes the study done with the permission of the FAA and airlines that showed there was always at least one cell phone on during a flight, if not more than one. Today, one would guess that dozens of electronics are actively seeking and producing signals in a standby mode.
Occam's Razor would suggest that avionic disruption would be commonplace with the sheer quantity and variety of devices across every plane model currently in operation. This has not occurred. The article doesn't discuss that disconnect between concern, repeatability, and reality.
I have an acquaintance who is an engineer with the FAA. About 10 years ago, he told me that the likelihood of such interference is so small, it is low on the priority list of what airlines should be concerned about. He said that before being certified to fly, one of the many tests an aircraft is given is to enclose it in a hangar and bombard it with RF transmissions at least 10,000 times as powerful as a cellphone, and if any of the instruments are affected even slightly, the aircraft fails certification.
I think part of it is just CYA on the part of the airlines. Sure, some new technology may change the RF situation someday, but it won't be "first time it turns on, plane goes down." That 'perfect storm' someone mentioned in the article is unlikely to happen before the possible effects this new gizmo could have are widely known, because it would be affecting other things, too. Like cars, trucks, watches, iPods, and maybe even toasters.