The guys at Playfuls.com have written up a lengthy preview of Neverwinter Nights 2, based upon what is known about the RPG sequel up to this point. An excerpt:
The henchman was the right hand of the hero in NWN 1, nothing to argue about on that one. Now, the producers offer the player a right hand, a left hand, and another hand placed somewhere only can imagine. Thus, the game becomes a party-based one: the hero now has three other characters under his command (three out of at least ten possible options). Like in KotOR 2, every henchman can be controlled from head to toes. The player has access to their inventory, he can dress the servants in shining armor, give them weapons, wipe their nose... err, well, you get the picture. Moreover (even though I don't know if this is good or bad for the gameplay), the player can control each henchman if he considers that the AI isn't capable of the same tactical subtleties.
As for the story, the helping guys will always have a well-settled role. Unlike the first NWN (where these characters were only killing tools, with a more or less vague story behind them), each character serving you will have its own path, needs and aspirations. The way they are treated will improve or deteriorate your relationship with them and will unveil another part of their past.