I see a fundamental flaw with most ergonomic keyboards; they ignore the need to use a mouse from time to time. All ergonomic attempts are ultimately futile if you've got to move your hand to the mouse every other minute, because some badly designed website or program or what have you requires you to click on something. The pointing device doesn't need to be the best pointing device in the world, but it needs to be readily accessible from the home row or your finger position.
That's why I think the Datahand is paramount. I've never used one, but I think I'd like it for the integrated pointing device alone. Ergo keyboards without pointing devices are ultimately stuck in the early 80s where there was no need for a pointing device. Heck, all keyboards without pointing devices are ultimately stuck in the 80s, and no fancy screen will remedy that.
If we swiftly ignore this issue, I think I'd fancy the µtron. Webwit needs to write a proper review, but from what I've read, it seems to be a "no hand movement" design, which is the only sensible thing to do. I've always been concerned by the large amounts of hand movement required for standard keyboards, especially with small hands.
Oh, and it absolutely needs spherical concave keys, because they're made of pure win.
-huha