I'm not so sure about that. They didn't give away the Nexus S (or any phone for that matter) last year, and I believe the Nexus S was launched around roughly the same time as the Galaxy Nexus was, relative to the date of the conference.
If they're giving away any phone at all, I'm guessing it might be a Galaxy S III, just because that's the only major phone that I'm aware of that's launching around the same time as the conference...
