Sometimes Visual Studio 2010 Beta 2 starts behaving badly. For me, Intellisense disappeared, but some people report other issues such as lack of response of Team Explorer.

 

For those and other ailments, the solution is to reset the Visual studio environment by typing this at the command line:

 

devenv /resetsettings

 

Of course, you must navigate to VS 2010 installation folder, which in my case is

 

"C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\"

 

You can find this and other related tips at this blog entry: http://blogs.microsoft.co.il/blogs/shair/archive/2008/09/03/reset-the-visual-studio-environment.aspx.