At this point, the solar system had essentialy the same form that it does now.
Since then, the planets and sun have undergone a lot of changes -- nuclear fusion in the sun, and chemical reactions on all the planets.
Asteroids, on the other hand, haven't changed much at all. Some of them, especially the C-type (carbonaceaous) and S-type (stony) asteroids, are made of the same stuff as the solar nebulae was. Eros is an S-type asteroid, and knowing more about its composition should help us to understand the details of the evolution of our solar system better.