From Entertainment Weekly (bugmenot has what you need, but damned if I could figure out where to use it – instead, I used my own subscription info to log in – but I’ve included the juicy bits below):
Lucas plans a second ”Clone Wars” cartoon. General Grievous, the villain of the upcoming ”Star Wars: Episode III,” will feature strongly in the five 12-minute episodes.
Did you like the ”Star Wars: Clone Wars” miniseries last fall on Cartoon Network? Did you see all 20 of the three-minute episodes and felt you couldn’t get enough? Then you’re in luck because the channel and Lucasfilm are teaming to bring out a second hour of ”Clone Wars,” this time in bigger bites. This time, there’ll be five 12-minute episodes, which will air over five consecutive nights beginning March 21, 2005, two months before the theatrical release of ”Star Wars: Episode III.”
The article goes on to say:
The two ”Clone Wars” miniseries follow the galactic civil war that began at the end of ”Star Wars: Episode II — Attack of the Clones,” between the Jedi-led forces of the Republic and the droid armies of the Separatists, led by the evil Count Dooku. While Yoda, Obi-Wan Kenobi, Anakin Skywalker, Mace Windu, and Padme Amidala all figure prominently in the miniseries, the character to watch for is General Grievous. The new ”Clone Wars” will prepare fans for ”Episode III” by offering them an extensive look at the general, the new character who leads the Separatist troops and is one of the primary villains in the forthcoming movie.