I think when they do start the move, it will be like they did when the ended mpeg2 Hi Definition. They will start by moving sports plans etc, and then by city, more so than simply ovine random national channels.
They've already started with some sports channels like NASCAR, UEFA, and like you, I expect some of the sports packages to be transferred over first.
... but I'm intrigued by their plans beyond them. HBO? Cinemax?! Starz?! Some of the LiL markets on 119 are smaller and less expensive to transfer over, so will they go that route, or will we see more aggressive moves?