Looks like there new version of a SiteMapProvider for MVC2 – see this link:
ASP.NET MVC – MvcSiteMapProvider 2.0 is out!
I’m not sure if it actually supports/respects the securityTrimmingEnabled setting, but it may be worth looking into. Also, from that page, I learned about this sample site:
MVC Music Store:
I downloaded this sample and checked it out. It does all the major things you’d need – like: showing a grid of data, viewing and editing data, and it supports the default membership provider, where you can log in and see additional content. If you know the gist of what MVC is, this music store is a fantastic "simple, but practical" example of how you might build a site using MVC.