Couldn’t find any thread for this. Hope it's not a vapourware. Here is the engadget link:
The prototype device is also only 6.8mm (0.27 inch) thick and weighs 385g (13.6 ounces) -- perfect for slipping into school bags. There's 4GB of on-board storage (with a microSD slot to increase that) and WiFi, which Sony plans to use for sharing notes with those who didn't make it to class on time. With WiFi off, the rechargeable battery inside is expected to last for three weeks of solid learning. These specs are for the prototype, of course, so after the late-2013 field trials at three Japanese universities.
Knowing Sony, I am sure it would cost a leg to buy if it ever comes out.