ICS for Nexus S! Hooray. Just did a manual upgrade.
We're rolling out Android 4.0, Ice Cream Sandwich, to GSM/UMTS Nexus S devices over the coming month, starting today. Enjoy the tasty update! Once you get the update, check out some tips and shortcuts for getting started at the Android 4.0 Help Center: http://goo.gl/5C0wM
Tips for Android 2.3 users - Help