I'm a fan of words, so I think electronic ink is about the coolest thing I've seen in ages. It provides for extremely high-contrast displays that finally make reading text a joy instead of a pain. The Sony Reader, due out in October for $350, is one of the first release pieces of hardware to use electronic ink to its full potential, and Gizmodo got their hands on one —color me jealous. In black and white.
One of the major benefits of electronic ink is no battery life is used while text is being displayed, only while it's being refreshed from another page. Thus, a single battery charge is reputed to last 7,500 page turns. And it's not just for text either; it can play back grayscale images in JPG and GIF format, making it a plausible platform for reading graphic novels (black and white ones, anyway).
Sony's also pushing their Connect store, which will allow you to buy DRMed book files from all the major publishers, but you can also load PDFs, RTF, plaintext, or an RSS feed (though there's no network connectivity, so you'll have to load them up via the USB port or the Memory Stick/SD slots). There's also a music player that supports MP3 and AAC, but I remain suspect: this thing's for reading , after all. It's in the name. Let's leave music to the MP3 players, shall we?