Back on topic, SpaceTime has been released...
http://www.twostunads.com/spacetime/
The demo version is only the various tutorials, but the app definitely has a huge potential. I'll probably buy the full version later today.
Only "problem" so far is that SpaceTime uses its own virtual keyboard : you can't use Transcriber (would have been great to write down an equation and see it drawn), or alternative text entry softwares like Fitaly or MessageEase (personal favorite).
The interface is incredibly polished.