SINCE THIS IS A HOLIDAY SEASON...they might be doing a lot of other stuff and just truly busy.
I say if you CAN wait then wait until the week after Christmas. They could be bogged down with figuring out Christmas bonuses, they could be planning a huge company wide Christmas party, they could be doing charity work for Toys For Tots, no telling what they are doing right now.
If this was August I would say call them on Tuesday. That way if they are planning on calling you next week they have Monday to do that.
BUT since this is a huge holiday season I would be a bit more patient. IF you CAN give it a bit more time that is. IF you are truly ready to move on and just don't want to be in limbo anymore than take that chance that they'll just say we're sorry, we're not going to continue with you at this time or they could say they were just finished getting the offer drawn up and would you like to go over it.