...Actually, I should amend that: I think the thing they're stressing is that that the new iTunes revision has the ability to "AutoFill" the tiny thing randomly from your library, so you have something close to the effect of full-library shuffle play as long as you keep syncing it every day.

They've paid attention to the fact that most iPod users bother with playlists little at all, and just shuffle their entire music collections. Of course you could always do the rough equivalent of AutoFill with a Smart Playlist, but Smart Playlists are actually beyond most users' willingness to tinker.