I came across this article a couple of days back, and found this to be a nice review, although a bit one-sided. The article takes the case of a long time Flash developer who got tempted to use Silverlight for a project. The article presents the problems he faces, and although he mentions in the end that he was not experience enough in the Microsoft and Visual Studio area, this should not be a roadblock. And he is right, since Silverlight is meant to take the battle to Flash, and it should have a great experience for somebody whose expertise on Flash. If a Flash developer found it difficult to move to Silverlight, it would just add another level of difficulty in getting Flash user to convert to Silverlight. Read the article at this location.
The article is a thorough criticism, not only of Silverlight, but also the efforts around Microsoft for improving the infrastructure related to Silverlight. For example, the article talks about how difficult and time-consuming it is just download and install Visual Studio. And the help and guidance provided was not very friendly.
Don’t dumb things down on my account, but understand that not everyone installing (rather, waiting for the install process to complete so they can use) your tools knows them well enough to get themselves in and out of your workflow with ease. Lower the barrier of entry and you may appeal to, and more importantly, enable, a lot more folks. This may be hard for you, seeing as your existing and historic developer contingent has already adapted to what I think is a very hardcore centered developer process.