Campaign coop?

I saw a video of people playing the single player campaign coop, yet when I go into the new multiplayer menu, all I get is an empty level or the ability to load some sample levels.

Am I missing something?

I asked this same question here:
and someone said that they likely got the campaign levels into the custom levels. Is there a way to do this?

is this going to come officially eventually - to be able to play the campaign levels coop?