Google has released an OTA update to the Nexus One called FRG83D. Unfortunately this update is just a 1.3 megabyte patch that updates the Market to 2.09, and is not the beloved Gingerbread release we are all waiting for.
The patch addresses some issues with the Android Marketplace framework and is not affiliated with any Gingerbread activity.
All that said and done... With Gingerbread seemingly so close to a release, couldn't Google have just waited? I think they just wanted to get people a little excited. So if you received the update then keep those fingers crossed that the next update will be Android 2.3.