I may be upgrading to the iPhone 5 when it launches, or when the fall rolls around. Whichever comes first.
I didn't purchase the iPhone 4S when it was released; I still have an iPhone 4.
On the other hand, nothing about the 5 that we've yet heard particularly blows me away, so I may purchase a 4S instead since it'll be much cheaper when I upgrade. I'm not here for a bigger screen either.