I don't have any plan. Also don't have a clue :)
They said the sensor is not replaced, but they didn't mention any other hardware being replaced. So maybe they need to swap some FGA's or something?
Distance information is known for the focus point, so maybe they can use that. For the OOF parts of the picture< I wouldn't mind a non-corrected image, or only CA corrcted.
Windows Phone 8 is already made by Microsoft, so why would you think they'll introduce bugs now they've acquired Nokia?
The 808 uses a 1/1.2" (10.67×8 mm) sensor, while the 1020 uses a 1/1.5" (8.8×6.6 mm) sensor. So the sensor area is roughly 32% smaller (or the 808's sensor is 47% bigger)