Just got inspired to throw one of these threads out early so its in the running.
I heard a dirty rumor that there won't be 'evolving' or involved story stuff like the good ol days, and, while there's a lot that has been done in game for piratey stuff, there's a lot remaining to be done.
Mounts - Cannon, Shark, Kraken, Mermaid, Parrot (done to death ik), Anchor, Dolphin, Seagull...?
Hats - Ridiculous pirate hats, bandanas, caps, eyepatches, indian headdress (a la peter pan), oversized hand-hook, seagull nesting,
Accessories - Ruffles (ahem hook), beards, telescope, cutlass, windlass, scroll cases, compass, chess piece (count of monte cristo), portable treasure chest, cannonball backpack, leather armor, brigandine armor
Furniture - Mast & Sail (long awaited by furniture community, might i suggest with a customizable sail or a sail with optional emblems), Cabin, Windows/portholes, the plank, rope coils, treasure, treasure map (with X), figurehead (for front of ship), dock, buoy, cannon, waterlogged table, skeleton crew members, gangway, deck planks, water tiles, helm/wheel, compass, sextant, large map (table/carpet size), wall hangings, crow's nest, rigging (climbable), etc...
Any other ideas, folks?