This article documents some of the key new features designed into Android version 4.0:

Android 4.0 – Five Features for new mobile O/S

QUOTE:  Android 4.0, Ice Cream Sandwich (ICS), is perhaps the most important Android release to date. With this release, Google has brought its tablet Android fork, 3.x, back into sync with its smartphone trunk, 2.x. In addition, all of ICS will soon, as I understand it, be made open source.  What that means for you is that independent software vendors (ISV)s can stop wasting time in developing two different versions of programs and focus their energies on making the best possible Android applications. Since, at the end of the day, the success of any operating system is all about its applications, this bodes well for Android.  Key categories of improvement include:

1) Better, more universal, interface
2) Better applications.
3) Speech transcription.
4) Better and faster Web browsing
5) Data use monitoring

Put it all together and what do you get? I think you get not just the best Android ever, I think you get the best mobile operating system of them all to date.