While surfing the internet I ran across some information which may be of interest to Nexus One owners who are patiently waiting for an OTA update to Android 2.2 on their Nexus One. In surfing the internet I was surprised at the number of Nexus One users who have not received any OTA updates from Google. I am not sure if it works but it may be worth a try. I was unable to test this on my Nexus One because I have manually updated my Nexus One to the most current build.
Give this a try:
Go to your dialer and type in the following characters: *#*#2432546#*#*.
On the notification bar at the top of the phone you will see a notification that 'checkin succeeded.'
Turn off the phone and turn it back on.
Go to settings - About Phone - System Updates.
You should get a notification that updates are waiting for you.
Let us know if this method works.