You can't use Cocktail in your console app if that's what you are trying to do. Cocktail brings dependencies to WPF with it. It might work, I've never tried it, but one really shouldn't. As it stands today, Cocktail only supports WPF and Silverlight clients. It doesn't support console apps and it doesn't support server-side apps. It is a framework to build GUI clients in WPF or Silverlight.
What I meant is that MEF is still available in console apps. DevForce does its part and creates the catalog and container which are available through CompositionHost.Instance.
So, if you have classes decorated with the [Export] attribute, they will automatically end up in the MEF catalog and then you can pull instances from the container, by using the helper methods on CompositionHost and/or use the MEF API directly to interact with CompositionHost.Instance.Container.