Finally, I can share a picture of how this may work.
A WebmasterWorld thread has a picture of how it works:
So instead of the bottom having click page 2, 3, 4 and so on, you get this button that reads "show more results" and when you click it, it will load the second set of results under the top result.
I kind of like it, how about you?
Forum discussion at WebmasterWorld.
Update: TiChou posted a video of this in action, here it is:
Confirmed: Google has confirmed it saying, "Google is constantly experimenting with new features."