One complaint I have is how difficult it is to just make a call! Swipe, swipe, tap, tap, scroll, tap, tap. I discovered how I could as a Contact as a Shortcut on the Nexus One Home Screen, and it made perfect! You couldn't do that on the iPhone. (In fact I heard Apple applied to patent it, but Android beat them to the punch, as reported by Engadget).
I also show off a little of the damage to my Nexus One that has been bounced around the playground a bit! I really need to find a good case for it.