There is a crash that can occur when you start debugging with Whidbey Beta 2 on a machine that still has remnants of Whidbey Beta 1. Judging from Visual Studio Error Reporting, quite a few people have hit into this.
You can use listdlls.exe from www.sysinternals.com to see what version of the interop assembly you have running inside of Visual Studio. If you are running Whidbey Beta 2 and you don't have 8.00.50215.44, then this is your problem.
>listdlls devenv | findstr /i Microsoft.VisualStudio.Debugger.Interop 0x5ed70000 0x2e000 8.00.50215.0044 C:\WINDOWS\ assembly\ GAC\ Microsoft.VisualStudio.Debugger.Interop\ 8.0.0.0__b03f5f7f11d50a3a\ Microsoft.VisualStudio.Debugger.Interop.dll
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Well, the usual reason why the debugger primary interop assembly is needed is for the 'Quick Console' window, so if you turn off the quick console, you can probably avoid the problem. To do this: Uncheck Tools->Options->Debugger->Redirect all console output to the Quick Console Window
You could also remove the old interop assembly:
rmdir /s /q %windir%\assembly\GAC_MSIL\Microsoft.VisualStudio.Debugger.Interop\
The new one will still be installed in 'assembly\GAC', so you should be good.