What is really needed is better multitasking, especially as the number of tablets running Android grows. I mean have it so that apps can run on a portion of the screen at half third or quarter size, so they can be used simultaneously. Maybe it needs to be more like an extension of the widget functionality, where each widget is basically a full app running. So you could have a word processor, pdf reader, and browser window open at once. Or phone and sms, or youtube and file explorer, music and a simple game. I think Windows Mobile can do this in some limited way.
It feels like people obsess over minor changes to the appearance of the OS or arrangement of a particular app, and forget that you need to rethink some of the most basic aspects of the UI from time to time to stay competitive as an OS.