1) More people probably have phones with them than regular digital cameras, so the “photographer base” is probably much larger. For more statistical anomalies, see C|Net’s take. Moral: it’s easy to lie / mislead with statistics!
2) People who have standalone digital cameras, especially dSLRs, probably take more pictures than people without; so I would guess a larger number of pictures are taken by a smaller number of people in that case. I would tend to guess they also take better pictures: not because of some magical quality dSLRs possess, but because people who know a lot about photography are more likely to buy better cameras.
3) Separate from the article, I have never seen a greater number of dSLRs than I did in NYC. Tourists, I guess? I never conspicuously hauled mine around. I wonder which city would qualify as “most photographed in the world;” perhaps Flickr or Facebook’s data hordes could answer. I would guess Tokyo or London.
4) Smartphones are clearly reaching (and, in some cases, have already reached) the “good enough” stage that so much consumer technology eventually does. I wouldn’t trade a Canon s100 or t2i for a phone camera, but in decent lighting the iPhone 4 and 4s do produce nice results. Note that interchangeable lens camera sales are up, probably because the Internet makes pictures more valuable for amateurs because of the possibility of sharing and perceived status gain.
5) The photographer still makes the camera more than vice-versa.
6) For any kind of composed shooting, a tripod will do more than anything except decent lighting, whether natural or studio.
7) Life is uncomposed, and capturing life might demand the same.
8) What am I missing?