Sandcastle Help File Builder v1.9.3.0 がリリースされました。
Sandcastle Help File Builder - Download: SHFB v1.9.3.0 Release
This release supports the Sandcastle June 2010 Release (v2.6.10621.1). It includes full support for generating, installing, and removing MS Help Viewer files. This new release is compiled under .NET 4.0, supports Visual Studio 2010 solutions and projects as documentation sources, and adds support for projects targeting the Silverlight Framework. ...
斜め読みですが、Visual Studio 2010のソリューションとプロジェクト、Silverlightのプロジェクトがサポートされているようですね。