Google’s reference platform phones (the Nexus One earlier and the Nexus S available now) have not been available from either of the U.S. CDMA carriers, Sprint or Verizon. And, despite this announcement from Google, it still isn’t available.
Google states that the Nexus S 4G (WiMax) for Sprint will be available this spring. Spring arrived this past Sunday (Mar. 20). So, it could make its retail appearance any day. The big news, of course, is the agreement between Sprint and Google to use Google Voice for all voicemail service (on any phone). Frank McPherson will have more to say about this later today.
As for the Nexus S itself, the only differences between the versions for T-Mobile and Sprint should be three radios for voice, 3G, and 4G.