While I cannot imagine it will be nearly as mature and robust as Monorail for some time, I do expect that it will have support for third party tools such as Telerik and CompontentArt, just to name a few. I have been able to run MR and ASP.NET in parallel, but in my opinion it adds too much complexity and limits the use of certain controls on which my applications depend. These third party tools I would rather not re-invent. In applications where I know I will not require these tools, MR is my chosen framework.

There are other MVC frameworks available, but it feels good knowing MS is going to provide their own and support it. Thanks to the community for making their voices heard for an MVC framework in ASP.NET.