AT&T wireless customers should really be thanking Apple and Verizon these days. Not only did the telco cough up 1,000 bonus rollover minutes to loyal iPhone customers just for sending a text message, they’ve now gone and doubled their 2GB tethering package at no extra cost.

MacRumors is reporting that AT&T is announcing via text message to iPhone users that their 2GB DataPro tethering plan has now been doubled to 4GB, all for the same $45 per month plan. The company was widely criticized for charging an extra $20 per month just for the privilege of tethering your iPhone to your computer, while having to do so from the same puny 2GB pool of 3G data provided by the $25 per month plan.

With the new change, DataPro customers effectively have 2GB for their iPhone use and 2GB for tethering, although unlike Verizon, AT&T isn’t limiting the data by how you’re using it -- you can use all 4GB for the iPhone, all 4GB for tethering or any combination of the two.

“Great news! Effective immediately, AT&T is increasing the amount of data included in your DataPro Tethering plan from 2GB to 4GB,” the company announced via text message to existing users. “The monthly charge for your plan will not change and no action is required by you. Thank you for being a great customer.”

Note that this deal isn’t just for existing customers -- new customers can add the DataPro Tethering plan at any time and get the new 4GB data pool.

While AT&T is often considered to be the ball and chain tied around the iPhone’s ankle, it’s nice to see the company responding to their new competition with Verizon like this. With any luck, the iOS 4.3 update will arrive soon and AT&T iPhone users can use their new 4GB data pool to enjoy the Personal Hotspot feature as well.

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