I used to feel like Apple needed to fill the size gap between the mini at 6GB and the iPod at 20gb, but have come to understand that they are correct to leave it as is. Either a person is content with having a decent cross section of their music collection to choose from (and 4GB is plenty for most people), or they want their whole collection at all times (and 20-60GB is fine). My guess is we won't ever see a nano with more than 6GB, or perhaps 8GB. I think we'll see a 100GB drive based iPod before too long, though. People who want to carry it all need more space.