Just posted this at another thread, but it applies here as well.
I live and work in Asia. For the last months every mom and her dog had an iPhone - or so it seemed. But lately I have seen a tremendous shift towards Samsung. Even after being on the market for only a few weeks, the SG3 has become wildly popular here, just as the Galaxy Note. Even petite Asian girls don't appear to have problems handling a 4.8" - 5.3" device (ah, did that came out right? ) No, seriously, the phone market has changed. It is not about Smartphones vs. Dumbphones anymore. That ship has sailed. These days the music plays almost solely in the smartphone segment. And for that, I believe it is a huge mistake by Apple to just offer one size. And a size, whis is in the lucrative Smartphone Segment, relatively small. If Apple releases only a slightly taller phone, then I am afraid, Samsung will eat Apple's lunch.
After all, Apple offers 11", 13" and 15" laptops, too. Variety, choices, catering for consumers needs. But only one size phone - and that relatively small.