When will a video or something be out ?
When they want to show off the game.
It's laggy still for a lot of people, including myself because unity's optimisation options are quite shit, so they're implementing their own optimisation menu. There's still a few bugs that need to be fixed too.
An in game teaser would be hard to make with game in its current state. They're releasing patches for us testers though, so I don't know, but I personally don't think anytime in the immediate future.
I'm under an NDA so that's all I'll be saying, probably even said too much.