It has arrived. (Thanks, ScottC!)
First impressions:
It's exactly what I expected, a DASH with HSDPA and a much better camera.
It feels faster as you zip around in the OS, zero lag switching applications, etc. The screen is quite a bit brighter. The keyboard is essentially the same, though the keys are slightly reshaped. I don't notice any difference in typing speed/accuracy.
With HSDPA it is FAST! Speed test of 302K/sec.
This I love: there is an option to turn off HSDPA but leave UMTS, presumably to trade off battery life and speed without resorting to EDGE/GPRS.
There is also a band selector with three options: US, Europe, and Japan.
It comes with a nifty RSS reader built into the home screen.
I'll post more once I've had a chance to play with it. My iPhone arrived today also so I'm quite busy.