I think Bruce Schneier might be overreacting here:
Okay, now the terrorists have really affected me personally: they're forcing us to turn off airplane Wi-Fi. No, it's not that the Yemeni package bombs had a Wi-Fi triggering mechanism — they seem to have had a cell phone triggering mechanism, dubious at best — but we can imagine an Internet-based triggering mechanism. Put together a sloppy and unsuccessful package bomb with an imagined triggering mechanism, and you have a new and dangerous threat that — even though it was a threat ever since the first airplane got Wi-Fi capability — must be immediately dealt with right now.
Please, let's not ever tell the TSA about timers. Or altimeters.
The two linked reports are actually pretty weak tea. The Gizmodo post is based on a New Scientist report, and the New Scientist report is basically sourced to one guy: Roland Alford, the managing director of "an explosives consultancy in Chippenham," who says he "expects" in-flight Wi-Fi technology to be scrutinized in future security reviews. And maybe it will be. Frankly, the TSA security folks wouldn't be doing their jobs if they didn't do at least that. But the fact that one guy thinks in-flight Wi-Fi will be scrutinized doesn't mean that in-flight Wi-Fi will actually be banned. Or even restricted. It's probably reasonable to expect the worst from TSA as a default reaction, but this particular report is literally based on nothing. I woldn't panic yet over this.