I love the idea of the Maormer being a playable race, so while I don't think it'll happen, I'd love to be proven wrong. Also, the sea serpent mount would be terrific but would have to work around the fact that mounts are made to traverse land not water...perhaps a mount that is relegated to the seas would be a great addition to a new expansion. (swimming is rather slow). As far as lore goes, I think anyone who's Vestige belongs to the Aldmeri Dominion has been teased plenty about the history of aggression between the Maormer and Altmer. Give us a look into the Maormer in their element; as to dissuade players from believing the idea that the Maormers' sole existence is the harass the High Elves. Tasks involving the Pact's, dare I say, allegiance, has the potential to go much further. Particularly due to the fact that the Pact's Navy is arguably the weakest among the Three Banners. That is of course, if you ignore the fact that the Argonians can breath underwater - which in all fairness, has been played upon during one of the quests involving the "Prowler". The maritime battle (also aboard the Prowler), was a personal highlight of the game and quite unique to Dominion players. Again, the potential to expand on that is huge and having it available via DLC would give players of other factions to have a taste without starting a new character. Pyandonea is certainly large enough to have a sizable expansion modeled from it. Also, of lands mentioned but never before visited in the Elder Scrolls franchise, Pyandonea is more local in regard to Tamriel than Akavir, and has only one dominating race. Now, while I think an expansion centered around any province of Akavir would be more well received than one of Pyandonea, I think one involving the denizens of the Eltheric Ocean could be more easily incorporated to the story line of ESO. This would include the Sload of Thras, whom both the Altmer, Maormer, and pretty much every other inhabitant of Tamriel resent. The Sload are experts of necromancy ( a central theme in ESO ) as well as great admirers of Mannimarco.

Anyway, with the recent release of "Orsinuim" all of my trepidation of new DLC just being an amalgam of already seen maps has been completely erased. If anyone cares enough to comment on or correct anything in my hopeful little rant please let me hear about it. If you are simply of a like mind re-post this in one of the many forums; maybe ESO brass will take notice.

MDJr1988