Photoshop is dominant simply because it is the best .But saying that most hobby and social photgraphers rarely need more power than Elements 3 & 4 can provide at a fraction of the cost of CS2 and Elements is built on the same engine as CS2 so you get the same smoothness and power which is why Elements is now the most popular editor in that price range.
I have CS2 as well as Elements 3 & 4 (I got 4 free from adobe as a beta tester) and Paintshop Pro X, but find I fire up Elements for most tasks.
By the way anyone owning PSP X should download the latest update as it at last sorts out the colour managment issues with that program.
