I would like to see the Yuuzhan Vong introduced as a faction in the near future. I know the ships are ugly as sin, but I think it would be a nice new set of play options. Not only by introducing a new faction, but new tactics. The Vong work differently than other era ships and it is my hope the rules would reflect this.
Having said that I hope Clone War Era is next, and I really like the idea of setting it up as Old Republic vs Separatist (not Trade Federation, they were absorbed into the Separatist after the war started).