I'm sure I'm not the first to think of this. And I believe there are some alternatives in the marketplace that do something similar (surfcube coming to mind). But here is what I think IE9 should do to make getting to your open tabs easier. You could also use this same concept to pivot to your favorites.
Windows Phone IE9 Improvement Idea- YouTube
Is there a way to embed youtube here?
Windows Phone IE9 Improvement Idea- YouTube
Is there a way to embed youtube here?