When there's enough ambient light, the screens can act in a passive reflective mode, much like e-paper devices such as the Kindle from Amazon (AMZN). This is great for a high-resolution black & white mode that can operate even in strong outdoor sunlight, enhanced with a form of "color hinting". But they can also operate in a more familiar active back-lit chromatic mode of LCDs.
This is a real game-changer for nearly every type of mobile device, but especially for transforming the future of tablets (think iPad, Android), netbooks and convertibles (think net/note-books whose screens swivel to form a tablet) into e-readers with all the functionality of a portable PC!
One of the issues with Amazon's Kindle (and similar devices) is that the electrophoretic displays have a very slow refresh rate. The result is that it's fine for e-reading, but it wouldn't work well for other functionalities such as video (think Harry-Potter-esque e-books) or even general application touch interfaces (which need quick UI feedback). So one has to wonder; either Amazon et al have to upgrade the Kindle to be essentially a fully functional Android-like tablet, or the future of e-readers is about to be subsumed by an ebook app on fully functional portable devices with state-of-the-art displays. This bodes very well for Apple (AAPL), Google (GOOG), and potential netbook partners such as Acer. But for Amazon, one has to wonder given the recent pining of publishers for a standard ebook format, if they'll hold their prowess in the ebook space...
As an aside, this trend also opens the door for some exciting re-branding opportunities for devices such as the FaceBook, the TwitterPad, etc. ;-)
Disclosure: no positions