Judging by the lack of reactions in here, I should perhaps make the point of this change more explicitly clear.
The nbody physics, in this version, is a lot faster than before. You can either have many more objects in the scene or you can have the same number of objects while having much faster simulation speed.
Seeing a pure managed cpu implementation with more than 50 thousand ring particles and one planet and 10 moons run at the framerate shown in the video is an extreme improvement. I dare anyone to try it with the current cpu implementation ;-)
As it is, this outperforms the current opencl implementation on beefy graphics cards as well.
Add to this that a new native cpu version is about 4 times faster yet, and that a new gpu version is also coming along...
In short: physics have grown organically in little steps and had grown into a less than optimal form. It is now essentially reshaped from scratch (keeping the recent collision changes though) and shows a huge performance improvement. Hopefully the required changes to the rest of the project can be completed soon, and it can be part of the next alpha. Perhaps it will take a bit longer. We will see.