I just got a chance to play with the big-screened, touchscreened Skiff Reader, which is targeted at periodicals. It's incredibly thin, incredibly light, and if a few issues get ironed out before launch, the Nook and Kindle should be scared.
I should add first that this is not a final version - they haven't announced pricing or availability yet - but it feels very finished and I suspect any delay in getting the Skiff to market will be due to the store not being quite ready.
Once you hold it, you're struck by how thin and light it is. Just a hair over 0.25 inches (6.35mm) thick, it's also super light and feels good in the hand - it's solid despite it's airy heft. The screen feels huge compared to the Kindle or Nook, because it is - its 11.5-inch touchscreen is huge, significantly bigger than even the Kindle DX (at 9.7 inches). The touchscreen works well, responding to both taps and swipes easily, and the refresh rate is pretty good (meaning, it's still e-ink, but it's not slower than existing readers). It can also handle 12fps animation, which is pretty primitive compared to LCD but just fine for little ads or whatever.
The layout is where it really shines - it feels more like a newspaper than any other reader I've tried. The layouts are designed by the periodicals themselves, so instead of looking like a bare PDF of text, it feels like there's thought put into the design. To navigate through a newspaper, you can navigate to a section with the "scrubber bar", a scroll bar on the bottom of the screen that displays each consecutive section's name as you swipe through it. It's great; you can go right to the arts section, sports section, whatever, and it feels totally natural. You can also swipe on each article to go to the next page, or swipe up and down to change font size. Highlighting and annotating both work well, and Skiff plans to automatically upload your highlights and notes to the cloud for access later.
Magazines don't fare as well as newspapers; it feels like nobody really knows how to digitise magazines. On the Skiff, magazine reading is pretty awkward - you flip through full page scans, then tap a page to zoom in, at which point you have to slowly and uncomfortably pan through the zoomed page, with the e-ink refreshing every time you move. It's not a good solution, but like I said, this isn't a final release and hopefully they'll have worked it out by then.
Books look fine, although clearly the Skiff is designed for newspapers; there's about an inch of blank space on all sides when you read a book, because 11.5 inches of text is a lot to stare at. Other than that slightly unfulfilled feeling when you see unused space, book-reading should be no problem.
The other problem I see is the store. The Kindle and Nook but waltzed into this world with massive and well-known stores behind them, and the Skiff is creating one from scratch. They've got a lot of publishers behind them, but the store right now is pretty bare. Of course, since it's not out yet, this may all be a moot point - but I wonder if their scrappy little store can compete with Amazon and Barnes & Noble.