What does this mean for you? If your a Popfly game creator, it means a much faster engine that is more consistent from browser to browser. That means you can add more actors and other craziness to your games. If your a software developer with a lot of code in Silverlight 1? Well, for you I’d say it means you should feel free to move to C# and Silverlight 2. It took me a couple months, largely on my own with about a month of help from Patrick to rewrite a large chunk of code that had been developed over the previous year or so by a team that grew from one to three (and occasionally more) devs. The cost was larger than it might have been because I also used it as an opportunity to re-architect and clean up the game engine, and I had to maintain compatibility with a large and complex set of existing data (the thousands of games already on popfly.com). I would expect that for most other Silverlight applications, the cost would be significantly less. What I got out of the experience was the vastly superior tooling experience of C# and Silverlight 2, a huge perf boost by moving to a compiled language, the maintainability of C#, the chance to follow the computer science adage of "throw one away”, and a much better code browsing and IntelliSense experience (again due to the fact that C# is strongly typed and compiled). My advice if your considering a similar move would be to take a look on what code you’re likely to touch again, and if you can see yourself working on it regularly, or if it has strong perf requirements take the leap.
If you’d like to hear more about Silverlight 2, working with the DLR, the port, or the engine, let me know in the comments and I can go into more details on the areas that interest you.