I doubt not having 4g will make a difference for most people, but you know the other phone manufacturers will have a negative marketing campaign against the iPhone which bashes the fact it doesn't have it.
Also, to the MOD, why would you be so against an update? It makes perfect sense to put in a few tweaks to the design/hardware if they needed to do so to bring the phones to new networks. If they can do it at similar cost to the iPhone 4 then you have some bullet points you can market while bringing the phone to new markets. Only makes sense.
What in the world are you expecting from an "adequate" update in your eyes? A complete overhaul to the best selling phone there is? Riiiiiight........
Is the lack of 4G really a deal breaker? I think the quality of hardware and iOS would still outweigh the alternatives for me.