Visual Studio 2010 Beta 2 Documentation is Now Available on the MSDN Web Site
See https://msdn.microsoft.com/en-us/library/dd831853(VS.100).aspx.
You can switch between the Classic, Lightweight Beta, and ScriptFree views of the documentation by clicking the orange Switch View button in the lower-right corner of the page in the Classic and Lightweight Beta content views and in the top-right corner of the page in the ScriptFree content view.
Enjoy!