[Hawk]

The 3Gs had many significant hardware updates, RAM, Processor, Camera, Magnometer, and a new infrastructure to support it. it's one of the reasons that there isn't a jailbreak for it yet, the hardware is that different.
Personally, even though the hardware update is significant, it wasn't for me. I honestly don't think the changes are enough for me to spend the money, even if I could afford it. I will update next year, but only if the phone is 4G compatible, as I will have it for another 2 years.
With next years phone, I think there will be a departure from some of the 3G(s) setup. I speculate a forward facing camera, dual speakers out the back, and a dual or quad core processor with 512 MB of RAM. But that is only speculation.
What I don't want to see is trying to make the phone smaller - unless the screen itself remains the same size. I think the size is perfect, I think that the materials could be better, and I believe that the next firmware will open even more possibilities that none of us have even thought of yet.