you can dock frames to other frames IE you can have a 2nd dock manager frame but i have not got that far yet
edit - just as Xrystal said lol.
note to Xry from what i was trying and looking at it would appear that somehow we can set a chatframe to be a dockmanager IE you could set the combatlog as the 2nd dockmanager i just have not figured out how yet or seen a function that does it... did you notice there are a few new files dealing with the chatframes in the bliz stuff? i have not looked over BNConversations.lua yet but it may have some useful functions for docking...