The GUI is wrong.
Don't get your hopes up. I doubt it will happen with the current ATV software.
With the album and movie extras GUI the way it is they would all need to be re-worked for ATV. If you noticed in the demo they use rollover image type buttons/links for navigation (looking like web pages). To do that on ATV you'll end up with focus rings around what's "active", jumping around like when you press the tab key on a keyboard.
Either that or something like pressing the left button on the remote to bring up an overlay navigation menu that's more like ATV, that duplicates all of the links on the current page.
Either way, for all the albums and movies involved, it sounds like a whole lot of work. I suppose you cold work it into Remote.app for touch devices, but not everybody with an ATV owns an iPhone or iPod Touch.