Update: We added a nice video of Sony' prototype device below
E Ink and Sony have co-developed a new plastic-based flexible E Ink display called Mobius. The Mobius panel uses Sony's flexible TFT technology, and will be produced by E Ink. Mass production of 13.3" 1200x1600 panels will begin in 2013. Those 13.3" panels will weigh only 60 grams - less than 50% of the weight of glass based panels, and will be much more rugged as there's no glass.
Sony unveiled a prototype tablet that uses those displays - aimed for the educational market. The A4 sized tablet (13.3") features a touchdisplay with stylus input, 4GB of memory (with microSD) and Wi-Fi. The whole device is just 6.8 mm thick and weighs just 385 grams. Sony hopes to start trials in three Japanese Universities later in 2013 and will hopefully launch it during the company's 2013 fiscal year (i.e. by March 2014).