Yes that is pretty impressive. You should be aware though that the entertainment value of the software will win out over the physics accuracy or even plausibility.
Even with our best modeling programs today, we are still discovering where they fall down and fail to simulate because we still don’t have the complete physics picture.
The difference is that academic programs strive to model as exactly as possible to get the best results whatever they may be whereas the Universe Sandbox will go for the visuals more and accuracy less.
It’s still quite cool. Will this be a game addition to Unity 3D or something to compete with unity?