Rather than lower the cost of AT&T's $70 per month unlimited iPhone data plan, the company may introduce tiered mobile data plans. Ralph de la Vega, President and CEO of AT&T Mobility and Consumer Markets yesterday said the plans would be similar to the subsidized netbook trials that began in early April in Philadelphia and Atlanta.

In those trial markets, the mobile broadband plans were $40 per month for a 200 MB data cap and $60 per month for a 5 GB cap, options that AT&T found "met the needs of casual to occasional data users, as well as frequent and heavy users." That is, of course, when coupled with Fast Access DSL service (also a part of some plans.)

Yesterday, the telco announced that it will be taking the subsidized netbook plan nationwide, with more than 2,200 AT&T stores carrying mini-notebooks by Acer, Dell, and Lenovo.

"Our customers in the Atlanta and Philadelphia markets have responded well and the response isn't limited to a specific demographic," de la Vega said in a statement. "We're getting interest from tweens, teens, young adults, moms on the go and small business owners. Consumers and small business customers really seem to be attracted to the convenience and portability of this connected device."

But talk of offering a variety of limited plans is sure to raise some questions about the strength of AT&T's network, especially after the sting of recent headlines that claimed too many iPhones have begun to eat up all the bandwidth at too low a profit for AT&T.

"Right now we continue to study what is the best thing that is available, not just from an iPhone point of view, but what you can do to stimulate additional demand," de la Vega told Reuters yesterday, "Our business is to sell services."

This announcement precedes what is expected to be a monumental week for mobile phone competition. Sprint will be making the Palm Pre available on June 6, and Apple's WWDC 2009 begins on June 8, where it is rumored that third-generation iPhone hardware will be unveiled with the new iPhone 3.0 software. While analysts expect the Pre will sell chiefly to Palm loyalists and existing Sprint subscribers, the mobile carrier has to contend with a critical case of customer drain. Simply put, customers leave Sprint, and customers go to AT&T. With variably priced data, a new rack of netbooks and the potential nuclear bomb of a new iPhone, AT&T has stacked up a fierce second week of June to compete with Sprint's Palm Pre launch.