Nokia Lumia 920 vs Nokia 808?

Tempting though it is to compare the two, aside from the 'PureView' label there's almost no common ground here at all. Ultimately, the 808 PureView will produce far better photos than the Lumia 920 in almost all light conditions, thanks to the huge sensor, PureView image processor and Xenon flash. But then the 808 is so far out in front of other phone cameras (apart from Nokia's own N8, also Symbian-powered) that it's in a different race entirely.

The Lumia 920's competition is phones like the Samsung Galaxy S III and Apple iPhone 4S - under ideal conditions, there's unlikely to be much difference between their photographic and video output. However, when light levels are low, with the optical stabilisation, the high power LED and F2.0 aperture, the Lumia 920's photos should be significantly better. With the moving subjects caveat mentioned above, of course.

That PureView label

Nokia refers to PureView 'phase 2' in its documentation, but even then stresses that it's complementary to the 'phase 1' technology (used in the 808). I think the 'PureView' branding is fine within this context, meaning (to the consumer) a camera with advanced technology - the exact details probably only need acknowledging by the tech enthusiasts.