It'll still be a decent camera compared to the competition
The use of the "pureview" brand following the 41mp 808 is misleading to some extent, essentially it's their version of the cybershot brand.
There is virtually no way they could have realistically transplanted that technology in to a svelte design like the 920.
It would have required an additional processor just for the camera.
If you read the white paper it does make some sense as to how they've tried to compensate, part 1 is using a lens with a massive aperture and 2 is to add OIS so that longer exposure times can be used. The focus is different, where the 808 was all abut detail and the ability to zoom the 920 is about low light performance and video stability. Lots of people take pictures in the evening at parties or outside blah blah blah so it's a sensible move.
I'm sure the oversized sensor(s) will return, it might take a while for that to happen, I'm fairly sure the 920 won't be as impressive a the 808 but despite all the marketing failings I suspect it'll be amongst the best if not the best mainstream smartphone camera out there.
Note that with this phone if you are prepared to knock down the output resolution you should still get some of that oversampling/lossless zoom goodness. A good quality 2mp image is completely fine for a standard print/web use.