Our group site Samsung Hub has published their hands-on impressions of the Nexus S. Released only in the US and the UK, Nexus S is always sold as an unlocked phone, and however you get a rebate if you buy it with a contract from carrier. In the UK Nexus S can be purchased with T-Mobile, Vodafone, O2 and orange. In the US it only retails on T-mobile. The one without contract costs $529 in the US and GBP425.99 in the UK.
The retail packaging of the phone comes with a phone, battery, USB cable, Travel Adapter, Manuals and a T-Mobile SIM card that can be activated till 2013.