Well there is the Anyths map. Similar to the campaign map you've already played except designed more for an epic brawl between all the factions on a larger than usual map.
Also, if you have the desire you can play the Wildlands map, which includes all the wildlands for you to destroy with the other players.
It also adds a few more stamps to help when generating some random maps. I cannot say if it is worth it to you, but there are some elements of fun included in the Map DLC.