I talked it over with some friends and it appears we're all gonna roll Eldar. Being the underdog (since orks get all the free boyz), Eldar will probably be the most diplomatic of all the factions. I'm excited to be a raider and kick ass all over the place in my wave serpent, neutralizing enemy resource nodes and chipping away at whatever we find. Hopefully I can be a Dire Avenger or a Ranger.
The faction with the most lack of humor are the Space Marines. There is nothing to laugh in the grim darkness of the far future, only war. Except the Space Wolves, I believe they realy enjoy their job.
Eldar, We once owned all that you survey. Our hubris knew no bounds as did our feats of creation and mastery of the warp. (The eldar know their past and are set upon to survive the consequences. The other races lack the perspective of age to understand their own folley, so we shall show them before they blindly stumble upon and unleash powers and events they can not hope to contain.)
Chaos, we are pretty young by standards in comparison to some of the people, but we live were once a mighty race of xenos were holding almost the entire galaxy in their hand, now i live in one of their homes and take long shits in their toilet as well as party all day every day. (Open the doors that have locks and see what happens, who cares we are part of chaos, we do what we want when we want we are free, too let the galaxy burn!)