1. Create a new MVC 4 Internet Application in Visual Studio
2. Install the ASP.NET SPA MVC 4 (Beta) package via Nuget Package Manager. After doing this, you should be able to buld and run the application with no difficulty.
3. Return to the NuGet Package Manager and uninstall the SPA package you just installed. Click 'No' when prompted about uninstalling dependencies.
4. F5
   

Result: You'll receive an unhandled configuration error after uninstalling SPA. The error message will read "Required attribute 'pageBaseType' not found" and point to the system.web.webPages.razor/pages element of /views/web.config. True enough, this attrbute was removed during uninstall.
Expected: Uninstallation should unwind installation to the greatest extent possible; in this case I'd expect incompatible section to be restored to a known good value like System.Web.Mvc.WebViewPage.