I was a little worried about the keyboard, but in landscape mode I can type with both hands just fine (and fast), in upright position its a different story, though it's still much better than on the iPhone.
Don't get it without the apple case, that one is really useful.
Yeah I am not using for serious writing or data entry so I am not needing to hit 40 wpm, but for a quick email (something I rarely do) or more likely posting on a forum) it works fine for me (for anyone who can use any phone or Palm like device) it's far more comfortable. Though I would imagine the larger your fingers are the more discomfort (though how anyone with huge hands could use a phone or Palm is beyond me).
I will say the one thing that did slightly disappoint me is the size of the device. It's fractionally smaller then I imagined.