We are starting off a new project with sitecore as our CMS. I was thinking of using Sitecore as the Content Authoring Tool and use ASP.net MVC as in the Content delivery(CDA
I think the real question you should be asking here is; if you already have Sitecore in place - why would you want the overhead and complicatino of introducing MVC?
Do you have any business requirements outside the basic web site that would necessitate MVC?