if you scroll down to the graphs about browser speed, you'll notice 3 bars, android 2.3, 4.0, and 4.0
Under the first two, it said Nexus S and under the third 4.0 it said Galaxy Nexus. SO, I'm assuming we'll either get 4.0 or the 4.0 browser.. thoughts?
Duarte/Google confirmed we're getting ICS (which is Android 4.0.x)! They said they're working on finalizing it for the Nexus S right now. And it looks AMAZING. They've improved so many things (GPU acceleration, notifications are finally useful, the camera, the browser is fantastic, swiping to close apps from the multitasking view, etc)
And direct quote from Gabe Cohen of Google:
"Currently in the process for releasing Ice Cream Sandwich for Nexus S. Theoretically should work for any 2.3 device."