I always thought Manaan was pretty boring, and I know a lot of people agree with me...
So without further ado I present to you the solution to the problem...
The Liberation of Manaan: A KotOR 1 Mod
After fighting your way through the Sith base, and Hrakert Station, then finding the star map and subduing the beast there (or poisoning it, whatever), your character returns to the surface. Near the Republic Embassy, you will find a Selkath by the name of Gossa. Gossa has a problem with the Sith, and he needs your help. The mod follows the fruition of Gossa's problem into something that could endanger all of Manaan, and give the Sith the upper hand they need to win the war. Beyond this, I cannot say, as that would be telling
What this mod includes:
A Brand New Party Member:
Meet Gossa, the new Selkath addition to the party.
Gossa is part of a secret bounty hunter organisation (I'm sure many of you will be able to guess) and recently was tasked with retrieving an ancient Sith artifact from the ocean floor. After doing so, things turned a bit sour for Gossa (as you will find out in the mod) and now he needs your help.
New Areas (retextures only):
There will be two completely new areas in Manaan for you to explore, a secret Sith facility and one of the many maintenance rooms that keep Auto City ticking over. (Screenies as they come)
The mod will feature hopefully another hour or so of gameplay telling the story of the Sith occupation of Manaan. You will decide the fate of the planet, among other things.
Several new major NPCs will be introduced, aside from Gossa, including a new Darth.
I've tried to keep this as spoiler-free as possible, even within the spoiler tags, to give everyone something new when the mod actually gets released.