Your link says 8.7 MP sensor, not 12. Nokia came out and said that their use of the term pure view technology is not really associated with any specific technology, just any system they make that gives good results.
If that doesn’t make sense to you, join the club.
I guess we’ll have to wait for the phone to actually come. I’ve seen conflicting reports as to what the camera will do.
I think it’s fair to say that it will take a nice picture.
Nokia says that the software that makes up pureview is in the Nokia 920, so it will give a better picture for sure.
http://reviews.cnet.com/nokia-lumia-920/