like others have said the problem isn't limited data usage or putting caps, but the actual cap number itself, what att has done is essentially put up numbers that fit in between most people and at the same time lower the limit for everyone
in the past the 5gb limit was in place and there was a supposed (reported) $50 charge if you went over, now honestly i'm not sure how many people actually ever went that high so it makes the penalty for the most part irrelevant
now they have moved the caps to 200mb and 2gb, chances are most iPhone users are going to be over 200mb ( i know they say 65% are not, but i believe that number is all smart phones, and a bulk of those numbers are corp blackberry users who get mail, so not much usage there, this statistic is very deceiving, just like all statistics tend to be) i would venture to say if you took all iphone users the percentage under 200mb is much lower
at the same time these average iphone users are also not getting close to 2gb, but probably more in the 600-800mb range, so in affect they are forced to pay for the 2gb plan.
the beauty of this plan though is at the high usage end, while the majority of heavy users probably didn't get close to 5gb they were over 2gb, so what they have now done is effectively raise the data charges through overages all under the guise of trying to make things equal for all, and as a service to customers. believe me, they are here to make money not to help people save money, they did plenty of studies and surveys to come up with these numbers and these are the numbers that best help them make money, it wasn't to try to help the little guy save $10 on their phone bill.
nothing but a trojan horse here, ii understand they are a business and they have to make money, and there is nothing wrong with that, but the misinformation and spin are the things that bug me.
also, keep in mind that the new iPhone and i'm sure future smart phones will start to support video conferencing/calls/live streaming/etc, so the bandwidth usage is going to go up. just think right now people are already racking up over 200mb just from browsing the web, what do you think will happen when you can actually use the phone for more that just check the news or browse a bulletin board.
and for those who say use WiFi, sure you can when you're at home, but that is about the only reliable place to get WiFi, the only other place is a college campus, otherwise unless you have a starbucks at every corner you'll find yourself hard pressed to find wifi on demand and at that point you've taken away 50% of the portability/convienence of a smart phone/iphone. the appeal is the on demand access, if you ahve to run around searching for a place to connect you might as well just wait till you got home and could get on a laptop/desktop