Im glad (well not really glad, but you know what I mean) that I don't have the money to spunk on the iPhone 5...... seems like a daft upgrade at the moment from anyone with a 4/4S.
I had my iphone 4 for two years and think the 5 is much better in comparison. It's just way faster doing everything, and feels a lot lighter. As for the 4S then I'd agree there won't be much of a jump, but there is a definite jump from 4-5.
I'm not one of those that pre-order either as I got it out of necessity (inadvertently killed my 4 and needed a new one ASAP).
It's good enough for a simpleton like me