The Penguin Group website has revealed the name of the previously titled 'Season Four Novel' due on October 27, 2011. And that title is...
Warriors of the Deep by Rob Valois! Click the link to visit the Jedi Journals page to get all the details we know. Amazon still has not updated their listing as yet.
It is also a good assumption, given the previous titles in Grosset & Dunlops
The Clone Wars line, that this title is the name for the first arc, or even an early episode from
The Clone Wars Season Four.