According to Engadget this morning doesn’t really say much, but does mention that the FAA just may consider reevaluating electronics during taxi and takeoff.
One of the key things it mentions which I had heard on Flyertalk before is:
Currently, airlines complain that they have to test each model of device individually, on every single plane in the fleet, and with a separate empty flight used for each test, before they’re allowed to relax the rules for that model.
I thought that sounded ridiculous, but apparently may be true. Considering airlines run on razor thin margins and are in the hole enough as it is, of course they don’t want to waste time on that since it doesn’t get them any more money.
Another key thing is attention. If you are reading your nook then you are not paying attention…but oh wait! If you are reading a paper book the same situation exists, and certain airlines such as United and AirTran allow you to listen to the IFE during taxi and landing (although they can interject in those systems)