According to a report by Engadget, Apple has hired Nokia's head of Lumia imaging, Ari Partinen. Partinen sent out a tweet saying today was his last day at Nokia and that in June he'll be starting "a new chapter in Cupertino." In a later tweet he confirmed the company he'll be working for in Cupertino is indeed Apple.
With their excellent optical image stabilization and high-resolution sensors that enable lossless digital zoom and clever downscaling, Nokia's Lumia devices, especially the 808 and 1020, are widely regarded as the smartphone cameras with the best image quality on the market. While Mr. Partinen's move doesn't mean we'll see PureView technology in one of the next iPhones, it shows that Apple is serious about camera technology in its devices.
The iPhone 5s is already delivering very good image quality without any optical image stabilization, large sensors or fancy software tricks. It'll be interesting to see what future Apple smartphones can do if Mr. Partinen gets to implement some of those ideas.