Karen Traviss has officially announced that she will write a 5th book in the Republic Commando book series! The title is Imperial Commando, and judging by the name of the book, I’m guessing that it will take place during the Empire.
Now in the RC book series, there will be:
Order 66 (comes out on September 16th)
Imperial Commando (Comes out at an unknown date, most likely 2009)
Karen Traviss also announced that she will write a post-Legacy book featuring Boba Fett