Phil, I think the relationships between WPF, Silverlight, AIR, Flex, etc are interesting, but not really the point I’m trying to make here. I would also argue that to focus on Silverlight as “just a browser plugin” misses the focus, as does calling AIR “just a desktop widget engine”.

The bigger point is not about the tech but about the users (remember them?) and how they are beginning to interact with the tools that are being presented to them; ditto about how we as developers can begin to build functionality which is build once/run many. The fact that once again a lightweight approach is the one gaining traction on the desktop is a pertinent one, I think.