The Ubuntu-Doc mailing list just received word from Dylan McCall and the Ubiquity Slideshow Team that Ubiquity (the Ubuntu live CD's installer) is being retrofitted with a slideshow that will play during installation. This is something I've supported for a long time and good news for new users, but it likely won't help anyone else.
The slideshow is written in HTML and CSS, and uses a main page to embed the other ones. The README file for the code indicates that slides should be 700x420 in order to fit on displays of 800x600. Since the PlaySlideshow.sh file only contains "xdg-open URL," I can assume the slideshow will appear in the default browser for the system being installed.
I've done a video of the slideshow for you to watch: remember that it's a draft and Dylan is asking for assistance on this.