Macworld [via] has a story up explaining that:
AT&T hopes to standardize on a single operating system for AT&T-branded smart phones as a part of a “dramatic consolidation” of its mobile platforms
...additionally, the statement was made by Roger Smith, who is the director of next generation services and product realization and therefore in a position to actually make good on such an extreme statement. Furthermore, he said this at a Symbian conference and suggested that Symbian would be a strong contender for that single platform.
Before you blow your top thinking that AT&T is planning on dropping Windows Mobile, the iPhone, and BlackBerry, we're wondering if there's a more prosiac (and less explosive) explanation. Perhaps the “branded” in “AT&T Branded Smartphones” actually refers to hardware, to stuff that AT&T gets made itself as opposed to stuff made by, you know, everybody else. In other words, if they do make good on these plans and they decide to go with Symbian (which we're doubting -- on both counts), you can expect to say goodbye to things like future iterations of the SMT5700. In other words, no biggy.
Then again, Smith does go on to complain about fragmentation, support, and the like. It may mean that AT&T intends on dumping support for the “non-AT&T OS” fully onto the manufacturers of said devices and focusing only on supporting whatever platform they decide on. That wouldn't be entirely crazy -- back in 2007 European carrier Vodaphone let everybody know they were planning on dumping everything except Symbian, Linux, and Windows Mobile in order to reduce support headaches.
Nothing like a vague and explosive statement from a carrier executive to spice up your Friday, eh?