The Nexus S has made it to the Google Website. More information can be found in the link below.
Of interest is that it will come with Gingerbread, ie Android 2.3 pre-installed. The website mentions a 4 inch display which is contoured.
Nexus S is manufactured by Samsung, and it is the first smartphone to launch with a Contour Display. The curved glass screen fits comfortably in the palm of your hand and along the side of your face.
Interestingly the Nexus S does not come with an expansion slot. 16gb of ram is available to you, but Nexus S comes pre-installed with quite a few Google applications, including Google maps, Google Search, Voice Actions, and Google Earth. We will have to wait and see how much ram is actually made available to the user.
My thoughts are that if no expansion slot is made available a 32gb version should also be an option.
More information can be found here: Nexus S