The Nexus One has already been confirmed as getting the Android 2.3 update at some point, and that time has been set for early Q1 2011.
The following announcement over on the official Google Nexus Twitter page confirmed the upgrade:
"The Gingerbread OTA for Nexus One will happen in the coming weeks. Just hang tight!"
Hardly the most revealing Tweet ever Twotted, but at least Nexus One owners won't feel too upset at having to wait ages for the new Android update.
The Google Nexus One is relatively similar to the Nexus S in terms of specs: 1GHz processor (although Qualcomm rather than Samsung's Hummingbird) and large high-res screen, so we should hope it's not too much of a jump to port the new platform to the original Nexus.