As Nokia's Kevin Shields mentioned in today's New York event, the key to taking good pictures is light. There are two basic ways to get more light with a camera. First, create a larger opening for light to pass through. The Nokia Lumia 920 will be fitted with a f2.0 aperture lens which allow more light to the camera sensor than the current Lumia Windows Phone models.
The second way to get more light is to leave the shutter open longer. To do this, you run the risk of camera motion blurring the subject. To help reduce this motion blur, the Lumia 920 will have image stabilization through floating lens technology. Essentially the entire optical assembly will be suspended and stabilized by springs. It will keep the lens steady for low light pictures.
Here's a quick example that was given... the first taken with a competitor's smartphone.
and the same shot taken with the Lumia 920 Pureview Camera.
It may not be a 41 megapixel camera but the Lumia 920's camera is very impressive.