The Beta 1 release for Visual Studio Orcas and .NET FX 3.5 is available for Download

From this MSDN site:

Visual Studio Code Name “Orcas” Beta 1
Visual Studio code name "Orcas" is the next generation development tool for Windows Vista, the 2007 Office system, and the Web. Beta 1 consists of multiple releases including, Visual Studio Professional Edition, Visual Studio Team Suite and Visual Studio Team Foundation Server, which are available as installation media ISO images you can use to install the products. Alternatively, you can download VPC images with the software pre-installed. In addition, you can download prerelease versions of Visual Basic Express, Visual C++ Express, Visual C# Express, and Visual Web Developer.

Get it here:
Visual Studio Team Suite-Only VPC
Visual Studio Team Suite with Team Foundation Server VPC
or from the MSDN Subscriber Downloads.

Watch this:
Conversation with Soma: Orcas Beta 1 and Beyond

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