First off, addressing the question at hand: Tracfone rates.
On CDMA phones Tracfone starts charging the second you start the call. Well, not exactly; they give you a 15-16 second "grace period" if you place the call during which you can hang up and not get charged. This is for busy signals and whatnot. Otherwise you're charged regardless of what happens on the other end of the line.
On GSM phones Tracfone starts billing once the call is connected. What this means varies, and there's no "grace period" but generally busy signals are free, as are most "no answers".
Now to the iPhone...
Granted, it's a great piece of technology. Sort of like iPod meets smartphone...but some people won't be comfortable with getting used to the onscreen keyboard, even if it is good, some people will be uncomfortable with the price ($500 for the 4GB model, $600 for the 8GB one, plus at least $60 a month for service) and some people will be uncomfortable th the fact that for the next few years it's stuck on AT&T. And of course you'll likely not see it on prepaid for a LOOOOONG time, GoPhone or no.Personally, no great loss; if you want something thin and smart, get the Motorola Q. If you want something REALLY smart, go with something built by HTC (verizon PPC6700, Sprint Mogul, etc.) and chalk up the added thickness to a nice built-in keyboard. And on Sprint you can get the Q or the Mogul for a fraction of the price of the iPhone and get a plan with an equivalent number of minutes for half the price of an iPhone plan.
In other words if you feel ready to drop $500 on an icon that doesn't run on a fast network unless you're within WiFi range, go for it...just remember you also have to pay $60 a month plus taxes and fees to keep the darn thing going...but there's really no need to bemoan the fact that this phone is gonna take a LONG time to make it to prepaid.