Nokia made a great case for Windows Phone 8 last month when it showed off its new Lumia models. The Lumia 920 was especially impressive with its amazing camera and neat form factor. Until now, we didn’t know if the Lumia 920 was going to AT&T, Verizon or both. Now we know that Windows Phone 8 will continue to stagnate on one carrier.

AT&T announced today that they are the exclusive carrier of the Lumia 920. The carrier said that they have sold more Windows Phones than any other carrier, and the exclusive nature of the 920 should prolong their status as the “unrivaled leader in Windows Phones.”

It’s disappointing that the Lumia 920 will be exclusive, but AT&T customers are in for a treat. Despite the stigma of being a Windows Phone, the Lumia 920 is quite nice. The phone sports a wonderful camera that Nokia claims can take in five times more light than other smartphone cameras. It also features software that keeps the dreaded shakeycam at bay.

“Exclusive to our customers and featuring unique innovations in imaging technology, wireless charging and a bright, sensitive display – all on the nation’s largest 4G network – the Lumia 920 will be one of the hottest phones for the holidays,” said Jeff Bradley, senior vice president – Devices and Developer Services, AT&T Mobility.

Despite AT&T’s confidence, will the Lumia 920 be “one of the hottest phones for the holidays?” Microsoft still has to convince people to buy Windows Phone. Most consumers equate the wonderful Windows Phone 8 to the dreadful Windows Mobile OS. The Nokia Lumia 920 is Microsoft’s best chance to disspel this notion.

We’ll find out in November if Nokia and Microsoft can turn Windows Phone 8 into a major player among mobile operating systems. The hardware is superb and Windows Phone 8 is arguably better than both iOS and Android. The only problem facing both now is the lack of software support from major developers. Smartphones live and die by their apps, and Windows Phone still hasn’t proven that it has the apps consumers want.