Here is a video that list some features in 4.0. No offense but the kids dorky but gives some insight.
http://www.youtube.com/watch?v=8QaK45L5n4g&playnext_from=TL&videos=fBeUXmOf2PI&feature=sub
http://www.youtube.com/watch?v=8QaK45L5n4g&playnext_from=TL&videos=fBeUXmOf2PI&feature=sub