We've published a three-page preview detailing Obsidian Entertainment's current progress in creating Star Wars: KotOR II: The Sith Lords. Here's a snip to get you started:
The Sith Lords features 7 new fully explorable planets, one of which you've already visited in the last game but will likely not recognize in its current state: Dantooine. Another new planet is Telos, the one Carth in the original game hailed from. Expect to see cameos and back-story filler from Carth, T3-M4, HK-47 (of course) and a slew of others who survived the last story. So does that mean Revan will make an appearance? This has been confirmed, but his/her story kept secret. One thing I wonder is whether they will make two different Revans, one of each sex for continuity sake.
Since many of the old characters will be returning in some form or another (but not playable), what do we know about the new companions? At this time, only a few of their names. Kreia is an older female Jedi (counterpoint to Jolee?) who can help you, and is apparently staying hidden from the Sith. T3-M4, the R2-D2-like robot from the first game will lead you through the tutorial sequence. Finally, Atton Rand is a roguish character, said to be similar to Han Solo from the movies. In all, you'll have 10 potential party members to pool from.