“iPhone is an innovative device that dramatically changed the game in wireless when it was introduced just two years ago,” AT&T Mobility and Consumer Markets chief Ralph de la Vega said in a statement. “Today’s decision was made after evaluating our customers’ expectations and use of the device compared to dozens of others we offer.”

It was also doubtless made after evaluating Verizon’s (VZ) announcement this morning that it will begin offering phones running Google’s (GOOG) Android OS and its Google Voice app in a matter of weeks. I’m sure that Federal Communications Commission investigation was “evaluated” as well.

Anyway, good news for consumers–assuming AT&T’s network can handle the additional strain, which is anything but a sure thing at this point.

UPDATE: The VoIP community was quick to congratulate AT&T for the move. “All of us at Skype applaud today’s announcement by AT&T (in an FCC filing to be published shortly) that it’ll open up its 3G network to Internet calling applications such as Skype,” Skype CEO Josh Silverman wrote in a post to the company blog. “It’s the right step for AT&T, Apple, millions of mobile Skype users and the Internet itself. Nonetheless, the positive actions of one company are no substitute for a government policy that protects openness and benefits consumers. We’re all looking forward to further developments that will let people use Skype on any device, on any network.”

The deal will put AT&T (T) that much closer to parity with Verizon (VZ), which surpassed AT&T to become the largest wireless carrier after its January acquisition of Alltell. Together, the two account for about 60 percent of all U.S. cellular subscribers. 

[Image Credit: IntoMobile]

Good thing, too. Because we’re just weeks away from the eagerly anticipated launch of Apple’s 3G iPhone and AT&T–Apple’s exclusive wireless carrier in the states–certainly doesn’t want to foul up the debut of the second-generation iPhone, the way it did the first. Because if it does, AT&T Mobility CEO Ralph de la Vega won’t be activating his own 3G iPhone until it’s been surgically removed by a doctor. Apple (AAPL) CEO Steve Jobs does have a bit of a temper.

Anyway … AT&T’s network upgrade is just six markets away from first-phase completion in 275 cities (second-phase roll-out will extend it to another 75). And when it launches, it will be the first and only network to run on a technology called HSUPA, or High Speed Uplink Packet Access. HSUPA should provide speeds of 1.4 Mbps down and 800Kbps up, which AT&T asserts “will be as speedy as logging onto the high-speed Internet service that many consumers enjoy at home.”

Hope so, because logging onto AT&T’s Edge network is about as speedy as logging onto the Internet with a 56.6 Kbps fax/modem.

So non-AT&T phones work on AT&T’s network. AT&T just didn’t bother to tell anyone–until all this talk of open-access wireless and Google’s open mobile-software platform, Android, made it a PR talking point. Your turn, T-Mobile.