So I just installed it last night onto my Motorola Xoom. Surprisingly, it looks and feels almost exactly like Honeycomb. I was expecting something drastically different.
Then I read up on it and it turns out the point of Android 4.0 was to put the look and feel of Honeycomb (which was a tablet only OS) onto the phones as well. 4.0 ICS is now a universal OS that can be installed on both smartphones and tablets. It's a pretty big change if you're going from v2.3 Gingerbread to v4.0 ICS though.
There are some pretty nice tweaks from 3.2 to 4.0 though. Better multitasking and app control. Smoother graphics. Improved browser and nicer app store. My tablet runs a lot nicer now.