I think it is a combination of the fact that most developers now have so much to learn and are more interested in the practical things they can use today like AJAX and LINQ. And I have seen polls that show most developers are waiting for Silverlight 2.0. I know both reasons are the case for me. Once developers have geared up on the initial technologies they can use immediately and Silverlight 2.0 is out and widely installed with web browsers, they will start to get into it. Before developers can really take Silverlight seriously there needs to be at least 80% usage. Having 95% would allow it to go mainstream like Flash is now. Perhaps MS can ink some more content deals like they did with ESPN.com to get more sites using Silverlight. A deal with Disney would go a long way to getting onto lots of home computers.