I currently have a 3GS. For me, the greatest factor, in deciding whether or not I should upgrade, is not the features or look of the 4S. It's the fact that I bought an iPad2 a few months back, and I'm using the iPad2 a lot more than the 3GS. My iPhone has become secondary, and, while I do use it, I use it a whole lot less than I used to. With iOS5, I could probably go another year until the next iPhone comes out. Still, it would be nice to have a better antenna, better battery life (compared to the 3GS), and better camera, and so I haven't quite decided. However, if I upgrade, it'll definitely be to the 64GB 4S.