If I understand things correctly, to use MVC Contrib's FluentHtml in my Views, I need to change my Views to inherit from MvcContrib.FluentHtml.ModelViewPage instead of System.Web.Mvc.ViewPage.
Will I lose any functionality provided by System.Web.Mvc.ViewPage if I do that?
I don't think so, as ModelViewPage inherits from ViewPage so will contain all the functionality. I just had a quick look at the source and there's no overriden base members so you should have everything from the base class intact and available.