On the website's FAQ page there's a question about the Clans and the answer is just: ";)".
Sure as hell better get to play as the Clans at some point. Clans rule, Inner Sphere drools!
We are Clan Wolf, children of Kerensky! We carry the honor of his name on our shoulders as our fathers did before us. The Remembrance speaks to us of the evil in man's will, of the reasons for Exodus, and the rights of the traveler. Arcadia is our destiny and our right. Enlightenment is our gift. By they bloodlines of the founders we must return, return and protect that which is unique among the stars! Terra awaits us as it was written. We are the last of the Wardens, the sole hope for the Earth.