Not much point yet
The screen itself may be (and is) very thin, but there's not much point in aiming for this if there is a fat base attached to it. The base is about 2 inches hight and 8 inches deep.
The screen needs to be completely detachable from the base in order to be of any practical value (ie - hanging on a wall, which, let's face it, is what it's ultimately aimed at).
The XEL-1 is a showcase product to demonstrate the technology, and in this roll, it works fine. But it's not actually of much practical value; in real terms, it takes up no less space than a more conventional flat display.