The Ice Cream Sandwich version of Android was officially announced May 10 at the Google IO developer conference. It's not expected to be released until the fourth quarter of 2011, and Google didn't offer up too many details, though it did say it'll bring features of Android 3.0/3.1 Honeycomb to smartphones. That confirms what former CEO Eric Schmidt said at Mobile World Congress in February 2011.
That's not to say you'll be getting the Honeycomb experience on a phone -- Android 3.0 was designed for tablets with their larger screens. But we should see some elements, such as the Action Bar and System Bar. Ice Cream Sandwich will unify the OS version across devices, and will allow for better application development on smartphones, tablets, and Google TV.
Nobody know much more about Ice Cream Sandwich at this point, but you can follow the news as it happens below.