Microsoft has posted the slides and videos from the 2008 Lang.NET Symposium that was held January 28-30:

langnetsymposium.com/agenda.asp

Description from the site:

"Lang .NET is a forum for discussion of programming languages, managed execution environments, compilers, multi-language libraries, and integrated development environments. It provides an excellent opportunity for programming language implementers and researchers from both industry and academia to meet and share their knowledge, experience, and suggestions for future research and development in the area of programming languages."