The EF 4 code-first demo has been updated to reference the EF4 Feature CTP3 dll at its default location. To run the demo, you have to make sure that the you have it installed. Download the EF 4 Feature CTP3 at http://www.microsoft.com/downloads/details.aspx?FamilyID=af18e652-9ea7-478b-8b41-8424b94e3f58&displayLang=en.
Although the demo was originally developed with VS 2010 Beta 2 everything works perfectly fine on VS 2010 RTM.
You can find the demo sources at github: http://github.com/martijnboland/EF4-codeonly-demo where it’s also possible to download the sources all at once.
Entity Framework 4 Code-First demo updated to Feature CTP3