Did MS ever expand the windows enviroment (windows forms)? Most of the expansion came from 3rd party tools.
Will Line of business developer use WPF? Sure some will. Will WPF provide any benefit? Not really. I’m still waiting for the articles and videos that show how WPF is going to make the presentation layer development better for line of business. Here is how I interpit WPF in line of business. Hey this is the new technology we have decided to shove down everyone’s throat. Its not going to reduce the amount of time you spend laying out or coding your presentation layer. Its not going to make your job any easier or provide you with any benefit. In fact its going to take longer be harder to troubleshoot and run slower.
From a line of business point of view WPF isn’t WOW its WTF