The Starter set is CONFIRMED to include two units of Sworn Brothers + Watch Captain (13 models each, for a total of 26), one unit of Veterans of the Watch (12 models), one unit of Ranger Trackers (4 cavalry models). And finally, the characters Jon Snow, Ghost, Jeor Mormont, Maester Aemon, and Bowen Marsh.
The two commander options are Jon Snow and Jeor Mormont.
The “gimmick” of the Army revolves around the use of Vow Tactics cards, which can be attached and removed from units. It seems as though the Night’s Watch will be “buffing” style army of some sort.
More to come as everything gets sorted out! Exciting news!