I have one. I like it, but android 1.6 is really crippling it. Once Dell deals with that, it will be great.
Dell markets it as a tablet, but it really isn't. I have found the experience to be much more like using a large smartphone than a full sized tablet.
I'll do a mini review here:
Pros: large, clear screen, very responsive touch panel, feels solid in the hand, extremely good battery life, built in speaker is much better than average, front facing camera, of course android
Cons: construction is lacking a bit (screen rippling if you press the top of the phone, a small light bleed point), uses pdmi instead of mini usb, audio quality isn't the best, accessories are uber expensive, still has android 1.6, some apps don't render properly on the high resolution screen, can get laggy in menus
Keep in mind that android 2.2 is going to be released for it sometime this year, which will get rid of the lag I mentioned, and make performance get tons better. Also, the apps not rendering properly is due to them not being written for a high resolution screen, so it is not the phone's fault. This would occur on any wvga phone.