Each time another asteroid, moon, or other odject is found, it is published in the science journals. The news media picks it up and reports at their discretion. This one is out near the Kuiper belt, so it attracted more attention, plus it must have been a slow news day. For all practical purposes, Earth is round. The deviation from a perfect sphere is very small. Few of the minor planets are close to round, having shapes resembling everything from footballs to totally irregular. Everything in the solar system orbits the sun, due to its immense gravity, even comets. Some orbits are more elliptical than others. Sedna's gravity is a fuction of it's mass, and being small, its gravity has no effect on any of the major planets.
As far as Astrology goes, I think the planets and other objects are more representitive of certain numerical, and vibratory nodes, whether or not a planet coincides with the position.