The successor to the Google Nexus One is here and will be available for American customers starting December 16 on Best Buy stores. But as you had heard already, the current version shall be on T-Mobile which means the Nexus S is only GSM compatible at the moment. However, rumor mongers insist a CDMA version too could be coming soon.
The source is presumably the rules and regulations posted for a Nexus S contest that is up on Google. A line on the rules page reads,
“The currently available Nexus S is a GSM device and is not compatible with CDMA networks such as Verizon and Sprint.”
It is being debated that the wording cleverly hides a possible Nexus S variant that could be available on Verizon and Sprint. However, that argument sounds too far fetched and is something I would not buy. Nevertheless, choices are always good and we hope this speculation indeed turns out true.