Silverlight 4 will be releasing to the web this week. While the first several releases of Silverlight seemed quicker than an electron in a collider, It does seem like each release is adding new discoveries to what can be done with Silverlight.
Also released yesterday was Microsoft Visual Studio 2010. Of course, this product has been available in beta format and pre-releases for many months. As such, while it is now officially released, information has been readily available for quite a while. Along with Microsoft Visual Studio 2010 is the release of the .NET Framework 4.0 with the new features of Visual Basic, C#, and more.
You can check out additional information on the new versions (Professional, Premium, and Ultimate) of Visual Studio at http://www.microsoft.com/visualstudio/en-us/.