Nobody (whose talking) knows, what we do know is that it's tied to the iPhone in some ways, and theres an iPhone update riiiight around the corner... Apple has a habit of showing us features we didn't even know we needed (wanted). If I were you I'd wait.
Also, I'm sure a lot of touch owners are waiting for the new iPhone to come out in order to move to an iPhone (like me), so even if a new touch doesn't come out, the used market will have more touches, and a corresponding price drop should follow.
Rob