I tested it last night, my first impressions were like this:

+ The super huge keyboard, (much faster to work with)
+ Jabber/gtalk support is great
+ voip (couldn't test it but it's there)
+ lots of applets, and you can customize the places on your 'desktop'
+ Applicition installer, uses source.list now, apt-get in xterm
+ install wizard, helps you on first boot
+ good for privacy (remove all personal data option in de the browser)
+ list of contact, for IM, email, and additional options if you like...
+ extends memory to mmc card (swap)

- voip I couldn't test it, reason works with gtalk and gtalk is windows only... (atm)
- google applet ... it is neat to have a browser that has the option remove all personal data, but if the google search applets doesn't do the same ...
- unstable (it's beta, reboots sometimes)
- screen gets dirty with the big onscreen keyboard
- flash ... well there is flash but offcourse not flash 7, so no video google

Conclusion... it is an improvement
and there might be a hint that nokia is a bit waiting for google or google for nokia...
there is an option to register a gmail/gtalk account, but for now, it just opens a browser and stays on about:blanc...