The battery life is almost exactly the same.One phone uses LTE, while the other uses 3G. I'm also ignoring how the 5 is easily faster than the 3GS, which requires more power.
All of the most popular apps still run on the 3GS, and run well, with the exception of a half dozen or so.
This will change as the 3GS doesn't get iOS 7 and other apps start requiring it (or a full-featured iOS 6).
The internet browsing speed is effectively identical, regardless of whatever the specs claim.
By virtue of the faster processor + GPU, this is patently false. Also, you'll get fewer Safari reloads since the 5 has 4x as much RAM.
The only features that the new iPhones have are things like Siri and Facetime, which are largely gimmicks with no real use case.
You forgot a faster cellular connection and a high-definition screen.
With that said (I won't speak to the camera, since I don't have an eye for that sort of thing), I agree that iOS updates since iOS 4 have not introduced gamechanging features. Still, it's nice to Facetime with my family given that we don't live in the same city.