They always offered updates in 100$ steps, and price wise the 64G is where the 32G would usually be. If they really kept the previous logic, the 16G would have been gone and the lineup would start at 32G, or we'd still start at 16G but the 128G would be 100$ higher than it is now.

That's on this basis that I was thinking, they couldn't get themselves to start the lineup at 32G. I guess it's the same pressures at play as for the 8G iPhones.