Alright. Then the iPhone 4 will eventually become the iPhone 4GS or something. Technology is continually growing. I got the 3GS because was watching my budget.
Yep, sometime this year, the new iPhone will be released. It will have the same guts as the iPad2 - a dual core cpu, and twice as much ram. Compared to that, the iPhone4 will be slower and less capable. It's the nature of the technology beast.
I just didn't want you to assume the 3Gs and 4 were interchangable. For example, the 3Gs cannot be used to do wifi internet sharing. It's lack of a front-facing camera makes facetime somewhat less useful as well.