Back in my day, a tablet was a tablet and an e-reader was an e-reader, and you could easily tell the difference just by looking at them. Well, looks like those whipper snappers over at Apple weren't content to leave it that way: they've gone and patented a hybrid screen that marries the tablet's LCD to the e-reader's e-ink display.
Of course, there's a long, hard road that gets you from patent to product, and Apple's display poses quite a few challenges thanks to its complex design. Not content with a simple toggle that would have you manually switching between LCD and e-ink, Apple wants its hybrid screen to know when it's best to use either and switch automatically, and even be able to turn portions of a screen into e-ink while leaving the rest as your traditional LCD for full color content and video.
It's ambitious, sure, but an e-ink screen is pretty much the big selling point e-readers use against the likes of the iPad. There are numerous small advantages, such as e-ink more faithfully recreating the experience of reading a book, and you can see text even under the blazing sun. There's also the fact that e-ink devices tend to last for days rather than hours on a single charge, and are far cheaper: a buck forty for the basic Kindle isn't quite the hit to the wallet as the iPad's $500 price tag.
Would it be enough to knock out the Kindle, Nook and the rest? Probably not. The message is clear, though: innovation is going to win this war in the end, not a difference in displays.