I received my new Nokia 800 yesterday, and got to play with it a bit. Apart from having been able to settle an argument about which CPU the XBox 360 uses (thanks Wikipedia), and toying with the chat apps, I've added a few apps to it, including a terminal (which will please my housemate), Chris' Dates, Tuomas' Plankton theme. No luck getting Plazer installed (some missing deps).
The web browser has a great resolution, and makes browsing large web pages easy, some bits of the interface are rather immature though (2 buttons to click to select the "Off" button action, the spinner showing up when clicking a link in the browser, etc.), and the application manager is a bit flaky and the error reporting blows.
The other disappointments, hardware-wise: no screen protection, apart from the sleeve (not really rugged), and the smaller power connector than my current Nokia phone (there must be some adapters so I don't need to carry 2 power supplies...).
The VMWare SDK image could turn out to be useful.