[@kingkonrad] Nope, nobody has taken control of the Lannisters. One of them showed up as a NPC, but that was just a GM puppet to help move the plot along, and they are one of the big players of this conflict. I'd love to see your seat. 

You can feel free to take control of additional characters as well, whether or not it's a house. There are multiple single characters that are important to the story but have no players. But thats up to you.