From an appropriately skeptical c|net article:
The Lumia 1020’s 41-megapixel camera represents an elegant solution to the dilemma of offering an optical zoom capability without a bulky, physical lens. While the PureView camera juts out slightly from the Lumia 1020’s body, it is no where near as cumbersome as the recently unveiled Galaxy S4 Zoom, which does include an actual zoom lens.
I’m glad someone is trying the novel hack of cramming an insane number of pixels into a phone-camera sensor, but it’s too bad Nokia’s the one doing it. They rested on their Symbian laurels while the market moved out from under them, and then they decided they’d go with the operating system that’s in a very distant third place. They probably aren’t going to make it for very much longer.