Microsoft has released an updated version of Visual Studio Async CTP

The Visual Studio Async CTP (Version 3) extends Visual Studio 2010, providing a new, streamlined syntax for asynchronous development.

The original Async CTP from PDC 10 brought asynchronous programming to C# and Visual Basic in Visual Studio 2010. This update brings the following:

Compatible with Visual Studio 2010 SP1, which is now required.
Compatible with non-English installations of Visual Studio and with Visual Studio Express.
Compatible with Silverlight 5.
Compatible with Windows Phone SDK 7.1 (Mango).
Compatible with Roslyn CTP
Includes various bug-fixes and changes, detailed in the Readme and documentation.

Includes a new EULA for production use. Note - This license does not constitute encouragement for you to use the CTP for your production code. The CTP remains an unsupported and use-at-your-own-risk Technology Preview. However, we’ve received many requests from developers to use the CTP for production code, and so have changed the license to allow that.

  Visual Studio Async CTP (Version 3)