It seems that some of the Microsoft GDC presentations are already available for download at microsoft.com.

• XNA overview (Brian Keller). An overview of the XNA initiative and how Microsoft is proposing to solve some of the problems. The last two thirds of the talk discusses design and content creation tool integration into the build process and introduces XNA Build and the graphical drag and drop designer that is used to define the build process. There is a demo of building the Mech Commander 2 source using XNA build. There is also some information on XNA studio with is a version of Visual Studio Team System targeted to game development companies.
• XNA Build CTP Tutorials (Michael Klucher). Michael walks through the XNA Build tutorials.
• XNA Build Advanced (Mel MacMahon). Looks like this a a sequel to the XNA Build tutorials talk. Mel walks through building Mech Commander 2 with XNA Build and talks about advanced ways to use the new tool

Thanks Mykre