Wordpress-like Plug-in model in ASP.NET MVC

This is kind of based off of this question.

I'm currently looking at rebuilding our company intranet from the ground up (I'll be honest, our existing one is an absolute mess), but one of the core "feat开发者_Python百科ures" of our new intranet that I'd like is the ability to build whole applications (which will also probably be in MVC 9 times out of 10, the other being standard webforms) as modules that provide additional functionality to the core or a module that creates a while new application within the core (for example, how Joomla does it) that just plug-in to the core application by say dropping them into a directory once they're completed, and at some point be able to enable and disable them from an admin interface.

I'm looking at MEF and trying to get my head around it at the moment, although I'm also taking a look at MvcContrib Portable Areas, and wondering if that's a feasible alternative for what I'm trying to do.

I was just wondering if this was the best choice for trying to get me to where I want to be or am I going about using MEF as the element to provide this function completely wrong?

Can I even do what I'm trying to do in MVC?

My personal preference is Portable Areas, but also have a look at the Orchard project in Codeplex. They have a very efficient plug-in mechanism, though somewhat complex.. It all depends on how much 'knowledge' of the core application you would expect authors of the plugins to have.