They key factor about Nokia's new PureView camera in the Lumia 920 is the optical image stabilization. From what I understand, Nokia put in a lot of R&D to develop an optical image stabilizer to be paired with their 8.7mp sensor. From the marketing hype, they were claiming it was capable of a degree of stabilization that rivaled that present in DSLR cameras (and lenses).
Technologically, the camera is nothing really "new". Optical Image Stabilization has been around for a very long time...its well-known and well-understood technology. The advancement with Nokia's PureView is that its been scaled down to a level as of yet unheard of, allowing OIS in a phone camera. The sensor, again, is nothing really "new". It is a backside illuminated (backilluminated, or BSI) sensor. This allows pixel area to increase relative to the size of other sensors with similar megapixels, improving low-light sensitivity, SNR, etc. BSI sensors are not new...the technology has been known for some time, and BSI sensors have been manufactured for small cameras including phone cameras for a couple years or so now. I am not sure I've seen an 8.7mp BSI phone sensor before, so the advancement here would simply be the number of megapixels packed into a phone. I do not believe the PureView camera uses "interpolation", as you put it...its actually hardware pixel bucketing, where the signal from multiple hardware level pixels are read out and combined to produce a single output pixel in the final jpeg image. Hardware level interpolation is more effective than software interpolation, and can produce better IQ overall as the algorithm is working with native, original signal at its maximum definition.
Claiming that the PureView cameras OIS rivals the technology present in DSLR's is a pretty hefty claim to make. The kind of image stabilization achieved by Canon in their latest generation of telephoto lenses is unprecedented and the current pinnacle of consumer-grade OIS, allowing a solid 4-stops improved hand-holdability and some pretty amazing results for video. The PureView camera in the Lumia 920 does not have to contend with a wide range of aperture settings, camera bodies, etc., so while it may perform superbly for the limited sensor and apertures of the camera in the Lumia 920...technologically and capably it is highly doubtful it rivals what is possible with a still or video DSLR in any respect.
Nokia's claims regarding PureView OIS have also put them in a bit of a bind, as they are currently caught up in a small scandal regarding their "demo video" of optical image stabilization...a video they did not directly claim was produced with the Lumia 920, but that they did not disclaim either. Thats lead to questions about whether PureView OIS is really as good as its been hyped up to be or not...and only time will really tell.
In the grand scheme of things, technologically, no, the Lumia 920 is not breaking any new ground. Its simply utilizing existing technology in new areas, or making better use of technology in the same areas its been used in the past. The hype that is forming around cell phone cameras is similar to the hype that formed around mirrorless cameras. Neither of them are going to topple the great DSLR. Different technologies for different purposes. I commend Nokia for adding OIS...even if it doesn't work as well as they claim, it will definitely help bring phone cameras into the realm of actual usability...think how many very blurry, motion blurred, and out of focus shots you see online taken with cell phone cameras that don't have fast enough apertures, sensitive enough sensors, or any kind of image stabilization to speak of. Something certainly needed to be done...but Nokia is simply taking an evolutionary step in the right direction. It won't replace your DSLR.