I've seen allot of analysis that shows the same line but as an analyst by day myself, I look at the numbers and how they are coming to their conclusions. All of them are counting the amount of photos taken by the type of camera and disregard the use.
Case in point -(For reference-for the last 10 years I have worked on installations of hardware in delivery trucks and took pictures of bar-codes and serial #s.) Up to 5 years ago I used disposable film cameras (8 photos per truck)- then 4-5 years ago I had a D50 (20+/- photos per truck)- 2 years ago I had an advanced compact (20-40 photos)- 1 year ago... My Blackberry(20-40 photos). I take allot more photos with lesser cameras as quality rises. But I'm documenting installs and not taking "good" photos. I also continue to use what is smaller and doesn't add more "stuff" to my travels.
Instances like this for work or little life things the counts go wayyyy up - hence the analysis of the usage for these articles seem to show things are being replaced. But... the market trend of sold units continue to rise for DSLRs on a whole. I think more people are documenting more things than ever and if the use is for documenting I would say that cameras are being replaced - but not for "good" moments at the lower end. At that consumer end a normal trend will occur - larger to smaller then repeat as technology continues to move forward.
Will evil and the Dslr dissolve into a hybrid camera - low end ones will, but the mid and high end models will still continue to exist due to the newest technology will always need more space.