I've asked the members of the Danish LUG "Byggepladen" (The Baseplate), and these ideas came up:
Soldiers Fregate = Big ship for the Imperials to fight Brickbeards ship
Port Royale = Minor civillian ship , a warehouse and a couple og soldiers - a little like the old Imperial trading post, but more civilian. A little carriage would also be welcome.
Pirate's Inn = A little inn with a couple of pirates, a bartender, a monkes and a parrot. And of course mugs with grog on the table and some barrels and packing cases.
Port Royale and Pirate's Inn should be build on some kind of a pier (like the new 6242 Soldiers Fort), so that they can be put together to a little town/habour enviroment - something we missed in the old Pirate series.
Big palm-island with a big cave for the pirates to hide the treasure.
Shipyard
Harbour
Something like this (from the LEGO Idea-book #260):
Small Pirate Boat
Small Fort (reminds me a little of LEGOLAND Billunds Fort
Smaller sets for a new wave could be
- a soldiers turret - like the old and charming 6265 Sabre Island
- natives in a canoo
- pirate in rowboat with a treasure chest who has arrived a little island with some natives
The natives can get some bigger sets in the next wave
Edit: Could someone fix the pics, please.