What you see here is the Launcher7 homescreen/launcher replacement app. And it's pretty darn good. You basically have two panes. On the left are the hallmark tiles that serve as application icons. By default you have phone, messaging, internet, gmail, music, Market, contacts and HD Video (gallery).
Flip over to the right-hand pane, and you get a list of all your installed apps.
There are a few basic settings, including tile color, and whether you want them to "fly" in or fade in. Font support apparently is in the works, too.
It's a cool little launcher replacement, and it's no secret that we're impressed by what Microsoft's done with the Metro UI in WP7, and the free Launcher7 is an interesting recreation. Now if only it could get me some Zune Pass on Android. ... We've got a video demo and download links after the break. Check 'em out.
ps: Note that you have to have an HDPI (high-res, basically) screen for this app.