Any new lands to explore? Other planets? More patrol modes? Otherwise why does Mercury have that one cocktease PvP map? There's a fundamental problem with paid expansions in multiplayer games: fragmentation. The more DLC required, the fewer the number of people available to play it. Either you end up segregating players based on whether they have it or not, or you have everyone included and people who have the DLC have less of a chance to play that content (e.g., one person in matchmaking doesn't have DLC; chances of DLC map being picked go to zero).