If you are a developer on .NET technologies, ScottGu’s Blog (http://weblogs.asp.net/scottgu/) is an excellent starting point. Scott Guthrie is a General Manager within Microsoft's Developer Division. He runs the development teams that build: CLR, ASP.NET, WPF, Silverlight, Windows Forms, IIS 7.0, Commerce Server, .NET Compact Framework, and the Visual Studio Web and Client Development Tools. His entries are always very didactical and precise: Probably the most up-to-date source of information about the newest developer technologies. Don’t miss it!
Tim Sneath’s (http://blogs.msdn.com/tims/default.aspx) and Mike Harsh’s (http://blogs.msdn.com/mharsh/default.aspx) Blogs are an important source of implementation examples with the newest client technologies. Go there if you want to know what you can do with Silverlight & friends!
If “Identity” is a topic for you, you cannot miss Kirk Cameron’s Identity Blog (http://www.identityblog.com/)