I bought yesterday my Nexus One from verkkokauppa.com. Local store has them on stock and they are US version, based on charger they have. I switched immediately sim from N900 to Nexus to check it out. What strikes me is lightness of that phone after N900, which is kind of brick.
First feelings are mixed, I still do not like touch screen only phones. Keyboards are so much better for serious typing and messaging. Other thing is that I just cannot like without N900's IM-support (jabber at first, skype in second). If there is truly working, open and integrated solution for Android, things get hard.
Reason for Nexus for me is some development things which I need to explore. I did some initial things with N900 and maemo, but it turned out so frustrating to hunt down information of certain functions on maemo.org. Let's see if Android is any better, if not - I start to solder my own phone.