I haven’t seen any tech blogs say this, thought it seems pretty obvious. I think we’re looking at the iPhone release cycle wrong.
What we see as a one-year release cycle that alternates between 4-style and 4S-style updates really isn’t. It’s two different two-year release cycles: one for the early adopter who likes the new form factor, and one for the person who values reliability over new features. The 4-style updates appeal to geeks (and other people) who love new, cool stuff. The 4S-style appeals to people who want the version with all the bugs worked out. Case in point: the iPhone 4’s antenna and the new antenna-switching in the 4S.
This way, the iPhone appeals to a wider audience. The cheaper, last-generation phones widen the audience even more with the same two 2-year release cycles, delayed one year from their full price equivalents.
For Apple’s target markets for this phone (3GS and non-iPhone owners), the iPhone 4S is as big a step as the iPhone 3G to the iPhone 4.
