VSTA DTEProvider has the ability to launch Visual Studio

In VSTA 2.0, you can use DTEProvider to launch Visual Studio instead of VSTA, which can be helpful for debugging or provide additional functionalities for users who already have Visual Studio installed. For example, in ShapeAppCSharpMacroRecording sample, in EnsureIDE function of VstaDesignTimeIntegration.cs you can change the code of

IDTEProvider dteProvider = 
             (IDTEProvider)new VSTADTEProviderClass();
this.dte = (EnvDTE.DTE)dteProvider.GetDTE
                                   ("ShapeAppCSharp", 0);

to

IDTEProvider2 dteProvider2 = 
             (IDTEProvider2)new VSTADTEProviderClass();
this.dte = (EnvDTE.DTE)dteProvider2.GetVSDTE
                                   ("ShapeAppCSharp", 0);

Read the complete post at http://blogs.msdn.com/vsta/archive/2009/05/17/vsta-dteprovider-has-the-ability-to-launch-visual-studio.aspx