I suspect the endgame is some sort of "we are all cyclons" thing. The 13th tribe were the original "humans and created the colonials on Kobol. The fought the colonials took off, built the cylons etc. That would jive with the "all of this has happened before, all of this will hapen again mantra".

I suspect when they get to earth, the folks there will be none to pleased....

"She's torn up plenty, but she'll fly true" - Zoe Washburn