Integrating ASP.NET MVC 3 into existing upgraded ASP.NET 4 Web Forms applications

I got an interesting question recently from a gentleman who has an existing ASP.NET WebForms 2.0 application that works just fine. He's upgraded it to ASP.NET 4 and it still works great, but now he wants to add some ASP.NET MVC pages to it. He doesn't want to rewrite the application.

http://www.hanselman.com/blog/IntegratingASPNETMVC3IntoExistingUpgradedASPNET4WebFormsApplications.aspx