Some much as been said about Silverlight and it's really good but sometimes we tend to forget an important issue like Performance, and being Silverlight a very interesting technology is very important not to forget any of this kinds of issues because when technologies are nice, and have great UX more hobbyists appear and more Best Practices are needed in order to maintain the level of success of the solutions developed.
As some of you might already seen there are several ways to take advantage of Silverlight capabilities, as by using it as a Rich island of ASP.NET solutions or developing full blown applications with Silverlight, but we cannot forget that the solution is processed on the client and so it will have to be downloaded by it, making the size a very important issue because you can develop a very nice solution using Silverlight but if it takes several minutes to download to the client, them probably you'll have a problem with it's adoption. And so this is why I thought of sharing with you an interesting post about Size Optimization of Silverlight Application files that was made available on the Delay's Blog.
Don't forget, Silverligtht is a powerfull technology but it has to be rightly used, and as Spider Man said "With great power comes great responsibility". :)