You have got to be kidding....Not true. No plan required for any smart phone they sell.
I'm a long time BlackBerry user on AT&T/Cingular/AT&T. They will sell you any BlackBerry, or Blackjack, or any other smart phone they offer without a plan.
There are thousands of people that purchased the small BlackBerry Pearl without a data plan. They bought it because they like the style, brilliant display, good camera, music player and great call quality. Since they only want it for a phone and text device they have no need for a data plan and AT&T is just fine with that.
Then if they wish to use it for the push mail, internet access and other features like exclusive BB PIN Messaging, they purchase the plan with the phone. Or later if that happens to be the case. No pressure or complaints from AT&T.
I am a long time BB user, with a BB plan as I use mine for lots of email, web access etc. Also AT&T gives BB users several choices of plans from as low as $29.99 per month. And that's an unlimited plan that provides all the emails and net access you can use.
AT&T can do whatever they want. If you don't like it then you don't get the iPhone. I guarantee the data plan will be REQUIRED. The ONLY unlimited DATA plan AT&T offers is $44.95.
Remember this is AT&T we are talking about.