Warning: this post is going to have a lot of conjecture, since it’s incredibly difficult (if not impossible) to get official sales numbers out of a lot of companies. And some companies (ahem, Apple) have a tendency to claim they are experiencing supply problems because demand is so great — presumably to create the illusion that they’re product is super hot. So while we may not be able to figure out exactly who has sold what, we can still try to make a few educated guesses about how the devices are performing.
Nokia Lumia
If you do a quick search, you’ll see plenty of articles saying “The Nokia Lumia 920 is out of stock!” But that’s not actually helpful – we still don’t know how many phones actually sold, or why they’re out of stock. It’s not a number, but BGR is reporting that the Lumia 920 was AT&T’s third-selling phone behind the iPhone and the Galaxy SIII in November. But According to the Wall Street Journal (subscription required), as of the bginning of December the Lumia has barely sold 100,000 units in China, the biggest smartphone market in the world. That’s troubling for the Lumia, since 100,000 units is nothing, and anecdotally China has quite a bit of interest in the phone, at least compared to here. Bottom line: the Lumia is not the hit Nokia hoped for, but it’s doing OK, and it will keep Nokia in the game until they can release their next device.
When we attended the 
The pairing of AT&T and the flagship Windows 8 phone isn’t too much of a surprise. AT&T carried the original Lumia 900, the previous Windows Phone 7 flagship device, and as the press materials note, “The unrivaled leader in Windows Phones, AT&T has sold more Windows Phones than any other carrier.”