Fair point on what is "mainstream". I was thinking in a US-centric way, I admit. Here the two best selling phones are iPhones (as far as I know).
But after thinking about this more, I just don't think it is helpful to analogize to the iPod. The difference in markets is huge, and I doubt the iPhone's share will ever be like what the iPod's was (and still is).
5% market share is not mainstream in mind. I guess I was referring to huge market share...