I've seen this transition used in Keynote, and I wanted to see how I could accomplish the same effect with jQuery and CSS3. I use jQuery for the animation, and CSS3 for the scale transform of the entire content area. The effect is one where the content area ducks into the background and a new content area slides in (from one of four directions, depending on the button you press). I tested this out on Chrome, where it is really quite smooth. Firefox and Safari on the Mac are a bit jittery with the animation, so that's something to look at before using this in a project. Certainly could use some re-factoring, but I'm pleased with how it turned out.
Practically, this could be used to enhance a site where the entire page content is being refreshed using Ajax, but illustrating a nice transition within the page after the Ajax request is finished.