i want to exchange my ipod nano?

Apple is usually very good about exchanging older versions of their hardware. The reason for this is simply because they want you to be able to enjoy their new hardware and software.

One thing that you have to think about though, is that an iPod Touch is quite a bit more money than the nano. And not only that, but the nano depreciates in value with every scratch and nick that's on it. So the answer is yes, you'll be able to trade it in, but only at a minor discounted price (MAYBE $25-50)

You can get 10% off the price of the iPod Touch by recycling your old one.