Does AT&T have iPhone exclusivity until 2012?

Rumors that a Verizon iPhone is in the offing are swirling again.

Tuesday morning a report surfaced that a company called Landor Associates is working on a branding campaign for the Verizon iPhone. That would makes some sense in accordance with a report earlier this year that an Apple contract manufacturer is working on a CDMA version of the iPhone, which is the network that Verizon uses in the U.S.

But how does that jibe with Apple signing a five-year exclusive contract with AT&T? USA Today originally reported the contract length in 2007, which would keep the iPhone away from other U.S. carriers until 2012 at the earliest. Engadget recently dug up court documents from 2008 in which Apple reiterates the exclusivity agreementwith AT&T that was previously published.

That would seem to imply there are still two years until Verizon could possibly offer the iPhone. But maybe not. It's 2010, and a lot has happened since 2007. When the contract was signed, AT&T took a chance on Apple's phone. Though it's been a runaway success, that wasn't guaranteed at the time for Apple, a company that had no demonstrated expertise in the area of smartphones.

The situation has evolved since then. Apple has sold more than 42 million phones worldwide, which has helped inflate AT&T's subscriber numbers. But the wireless provider has struggled with the extra traffic on its network, forcing Apple to publicly defend its carrier partner, but privately have discussions with itabout working out the problem.

It's very possible that the terms of the contract between Apple and AT&T have changed since the original five-year agreement. Does it mean Apple has canceled the contract two years early? Perhaps. But we don't really know. There was a hint that AT&T made some concessions to Apple, however, when the iPad was introduced.

The iPad 3G is also tied to AT&T in the U.S. But the terms were surprisingly different than the plan customers need to agree to for the iPhone. The iPad 3G offers optional, month-to-month data plans through AT&T, no contract necessary. And the prices were legitimately good: $15 for 250MB per month or $30 for unlimited data use for a month. Did AT&T agree to this as a last-ditch effort to keep Apple from running into the arms of Verizon? Again, we don't know.

The only thing Apple will really say publicly about additional carriers is in broad terms on earnings calls. COO Tim Cook has said two different times that though Apple has seen increased sales in countries where it has added a secondary carrier, it doesn't mean the results would be the same in every country.

"In each case we've done that, we've seen unit growth accelerate and market share improve," Cook said in April. "But that doesn't mean we view that formula works in every single case. That's our learning so far, but we think very carefully at the country level to conclude what's in our best interest."

That could be Cook avoiding giving any real hints about Apple's plans. Or it could be the sign that Apple has plenty of room to renegotiate its carrier contracts.