Back when Google's phone, the Nexus One, withered and died, it seemed like the idea of a Google phone was a foolish lark that had failed miserably. Not so. Google comes charging back with the Nexus S (Google said they didn't want to be "Nexus Two" because they hate being number two), which is made with the help of Samsung. The "S" is also a reference to Samsung's own Galaxy S, which the Nexus is sort of based on.
It's $529 unlocked or $199 with a two-year T-Mobile plan.