It's gonna be years before everyone has an iPhone 4s and up and I wouldn't buy it just for what the future holds for the platform. I like my iPhone 4 just because of the iOS interface but you might want to shop around for better deals unless you're willing to pay a premium price like I did. If it wasn't for the iPhone I'd probably either be on Sprint's network which is 70 dollars for unlimited everything, Or Virgin Mobile which is 25 dollars a month no contract for 300 minutes and unlimited text and web. This is a big contrast to what AT&T offers because they charge quite a bit more than Sprint for for limited text, minutes, and web.
This. If you are still thinking of selling in September, and if the new iPod doesn't have a camera, send me a message.