WBIE offers details on Batman: Arkham Knight Season Pass and the Premium Edition of the superhero game, both of which are now available for preorder. Word is the Season Pass will include a six month DLC run, though they don't state how many releases this will include:

Warner Bros. Interactive Entertainment and DC Entertainment today announced the Season Pass and Premium Edition for Batman™: Arkham Knight, the epic conclusion to the award-winning Arkham trilogy from Rocksteady Studios. Both the Batman: Arkham Knight Season Pass and Batman: Arkham Knight Premium Edition are now available for preorder from participating retailers. The Season Pass is priced at $39.99 and the Premium Edition, which includes both the Season Pass and the main game, is priced at $99.99.

The Batman: Arkham Knight Season Pass will deliver regular new content for six months post-launch including new story missions, additional super-villains invading Gotham City, legendary Batmobile skins, advanced challenge maps, alternative character skins, and new drivable race tracks. The Batman: Arkham Knight Premium Edition includes the main game and the Season Pass.