Right. There has been significant progress. The planetary system has begun to rotate. And it isn't simply moving according to a script: it follows Newton's laws. The mechanism works both on the client and on the server, because the calculations use standard three-axis coordinates scaled for the client. The planets move in their proper elliptical orbits, inclined to the ecliptic, with the expected changes in speed at apogee and perigee. The accuracy is quite close to scientific calculations.
I also managed to link time scaling to real time and the rest of the mechanics. Now we can run in real time or turn a year into a second.
I especially like that any object added to the system automatically becomes subject to this whole gravitational dance and starts moving accordingly.
Soon I'll try flying around the system in a spacecraft.