There is a ring of about 50 specific patents around "pureview", what they are exactly I don't know, but I would imagine that it will hard to replicate the same exact thing unless you either license the tech (if its available), or use them without permission.
There aren't many ways to make a better camera phone other than using a bigger sensor, or using a completely different sensor technology which is not dependent on sensor size.
Considering that all OEMs are obsessed with thin phones, I don't see anyone going for a bigger sensor.. maybe Sony or Samsung, but it wont happen in the next 12-20 months.
As far as new sensor technology.. I have no idea. I know that Nokia patented a few graphene sensor concepts a few years back, but that doesn't mean anything..
I mean that it works perfectly fine as a smartphone.. it even has a fully functional music player.. imagine that..