Remark: Not a "scientific" review
Now, I used this camera to have fun with it - i did not do any lens chart test pics, pixel-peeping etc. Neither do I have the technical means to make such a test nor do I want to make it. If you look for this, just google around, you will find hundreds.
As you probably know, one of the selling points of the 1020er is the built in camera. Here are the specs taken from the Nokia website:
How can a mobile phone have a camera with 41MP?
The idea behind this number is simple: its difficult to build a zoom lens in a thin mobile phone. Zooming digitally is quality-wise really crappy - so: take a high-resolution picture (with 41 MP or 34MP as Nokia shows in some screens) and zoom after taking the picture. There are enough pixels left and the quality of the lens allows for this. At any time you can go back to your 34MP photo and recompose/crop a new version of the 5MP.
Combined with sharp Zeiss optics, an image stabilisation mechanism (you can even hear the lenses shuffle when you move the phone) makes a quite capable camera on paper.
Now if you e.g. upload your photos to skydrive, the 5MP version gets uploaded automatically (3072x1728 pixel). To get the full size images you need to connect your phone via USB and copy them directly.
But I shoot RAW!?
Since I work as a photographer I was blown away to hear, that Nokia is providing us with RAW DNGs out of the mobile phone camera soon: see here. Unfortunately so far I was not able to test this.
The Lumia 1020 camera allows you to control ISO and shutter speed manually. You still cannot change the aperture, but at least you can decide between ISO and shutter speed in your pictures.
Camera Software that comes with the Lumia 1020
The Lumia 1020 comes with a huge pack of apps that help getting the most out of your camera. I recommend using Nokia Camera for taking your Pictures. I played around with the Nokia Smart Cam but was not able to get real stunning results so far - but they implemented nice ideas and I was just using it in the wrong context.
Unfortunately I have not found time yet to test the Nokia Cinemagraph, Nokia Creative Studio and the Nokia Panorama.
My personal experiences
It is fun to play around with the Nokia camera and the quality is impressive. Though an additional review of the rest of the Nokia software suite is needed ;)