Here in Canada where the oligopoly of telcos locks you into 3 year contracts many people in my family still use their 3GS. In fact everyone in my immediate family with an iPhone has the 3GS (as did I until May when mine broke). Also worth noting that the 3GS has been sold up until this very day.
Some Canadians have been upgrading from the iPhone 3G this fall as well, which was sold up until summer 2010. My coworker just got a 4S and gave his 3G to his mom who now loves it.
I have no idea what it's like in SF and other similar places but there's a big world outside of California.
But this is exactly his point. Only in mobile devices is 3 years considered old to the point of irrelevance, and Android is far worse, closer to 3 months.
It can be justified on technological or economic grounds, but either way, environmental sustainability considerations clearly don't enter into the equation.
3 months for an Android phone be irrelevant is absolutely not true. My girlfriend has a Galaxy S (released June 2010) that runs every single game in the Android Market perfectly and was updated to Gingerbread (and maybe will be updated to ICS). It is not the best device out there but is still very relevant and she doesn't see a single reason to buy a new device.
I don't believe you can downgrade to 3.1.3 any more. When you restore an OS image, iTunes checks whether it is a valid image with Apple's servers. After a major version has been out for a while, Apple stop approving installs of older versions.
Wow, thank you for the suggestion! I'll definitely be trying it. I can survive with webapp Twitter until my next upgrade (or even next year for the new iPhone if it's bearable enough).
You're looking at only the launch date, whereas there are still people who are locked into carrier contracts after having bought it. AT&T stopped selling it only in June 2010 which is not even a year and half back.