Didn't Bethesda say they were done with expansion packs and were focusing on DLCs instead?
For Fallout maybe, but knowing Todd and the boys, expansions are probably already forming in their minds. Personally I'd like another province to become available in an expansion, such as Hammerfall, since it is right on the border. Of course this would be an enourmous undetaking for an expansion, so we'll see.