Spertallica
Rear Admiral
The Cylons *aren't* just "genocidal machines" anymore. Caprica six and Athena have shown us that the humanoid Cylons are so similar to humans that they have the same broad emotional spectrum that humans do. Obviously the war with humanity didn't turn out as simple as they initially thought it would be.
Besides I always figured they were heading to Earth not so they could interbreed, but so they could cleanse the Earth of humanity and live there themselves... kind of the final victory over the human race, knowing that there are no more humans left in the universe.
Then why do they bother with the whole interbreeding program, or having that one male cylon come on to Starbuck like 453 times in season 3? (and getting killed almost every time for his efforts!) Or the prison camp? Or keeping Baltar alive? I'd like to think there is a schism between the cold, rational, machine cylon mind and the unpredictable, emotional biological cylon mind... it's the only thing that could explain half the senselessness of the second half of the series.