One level is one too many. That Apple has resorted to pages in folders, and is now considering more folders in folders, should be reason enough to for Ive to scrap this whole 'homescreen with icons' design.
I agree. It would be illogical to allow one more level ONLY, because then people would ask why. I do think pages on a folder as being a little odd too, but I see JTS' point about each folder being a mini home. Maybe they needed to just do something different in a folder like just having it scroll.
Maybe eventually we'll see a non-icon-based home screen, but apple is typically baby-steps about such large adjustments.
I still enjoy the app-based home screen. The whole premise was that they were 'buttons' on a changing UI. That said, it made more sense in Steve Jobs 'stock' iPhone, the one that didn't run third-party apps. Now that it really is a whole platform, maybe it should evolve to be more of a mini computer. Like have something more akin to a lock screen be your 'home'. I.e android.
I mean, if they reckon it's time to no longer need the skeuomorphic cues to teach people to use iOS, then it could be time to move entirely from the whole 'app-buttons' too. But yeah, baby-steps.