As I am a follower, Apple does a great job in getting you to believe that you must have their lastest product. Before the iPhone, it was the G5 Intel Quad, the iMac, and of course the iPod. The iPhone is amazing, but it is just a phone. The G5 is very fast, but still a computer. The iPod, well, that was as revolutionary as the original iMac in '84.
I own a G5, several iPods and when my wife buys me the iPhone for my birthday in September, the iPhone. Frankly, i'm happy with the phone I have, but love the screen size, wifi, and surfing the net capabilities of the iPhone. If the next gen iPod did that, I keep my phone and just by the new gen ipod. Of course Apple is well aware of this fact which would hurt phone sales, thus, it will probably not happen.
It'll be interesting to see how Apple handles the next generation iPod. For me, I'm really waiting to see when Steve stands up their next January and introduces their revolutionary TV set. Has to happen, right?