Three Del Rey Star Wars books appeared in Random House's Spring 2012 catalog, and one interesting bit of news is that Troy Denning's Fate of the Jedi: Apocalypse will contain an "extensive excerpt of book one of [the] next Star Wars series." Apocalypse is set for an April 2012 release. So far, all we know about the next series is that it won't be another nine-part story.
The Legacy of the Force series ended in May 2008, and the current series began with Outcast in March 2009. If the same timeframe applies again, we should expect the next series to debut in early 2013.
The other two Star Wars titles featured in the Spring 2012 catalog were The Essential Guide to Warfare by Jason Fry and Darth Plagueis by James Luceno. You can click the thumbnails below to see full PDFs of all three Star Wars pages.