Mattieu Mezil show how to use TypeDescriptors to make FK work in EF 1.0.
In his 30th tip, Alex James shows how to use database functions in EF 1.0 and EF 4.0.
The ADO.NET team presents the improvements to the generated SQL for Entity Framework.
Phil Haacked shows how to focus in View pages on presentation concerns by moving Page declaration to web.config. He also shows a prototype of default templated views that we might have in the future bits of MVC.
Kirill Osenkov points out the C# compiler team blogs.
Chris Burrows has a nice post about dynamic base classes.
Eric Lippert has another bunch of excellent articles: