the teardowns on the internet concretely prove that there are no 3G or GPS chips/radios in the current iPhone. 3G will NEVER be a software upgrade for this model in the way Airport was for 802.11n. Period.
BTW, that article says the software update will be "before Leopard in two months" not at the end of next week. I think some of those features may be fanboi speculation too, like a full file browser/finder built in.