Apple recently updated the App Store and iTunes store for the iPad to include a new swipe interface. Featured apps and songs can now be explored by swiping, instead of pressing arrow buttons. This change may prove to be significant in regards to folders. Astetichally, these new swipe sections of the store look very similar to a folder when open, which is may prove to be important. If people intuitively know to swipe these sections left and right to reveal more, they will also know to swipe folders left and right to reveal more. Now I'm not guaranteeing that folders will get expanded like this, but if it were to happen, it would be a very easy to understand transition and would be consistent throughout the os, something that Apple is very keen on.