So we just snagged our Kindle, and we're unabashedly stoked to get using it. Unfortunately the device came out of box with too little juice to get on the EV-DO network, but the e-ink display looks great (as we'd expect). The selector bar on the right is really interesting; it appears to be a white, opaque thin LCD panel that polarizes and turns clear letting reflective dots peer through -- the end result is a small selection bar that looks unlike anything we've seen on a portable reader device.
The keyboard is clicky and tactile, but with keys shallow enough that they won't get too in the way when you're reading. We're a little worried that the absolutely massive page forward / back buttons might get inadvertently triggered here and there, though.