Del Rey's Star Wars team has confirmed that the novelizations of Star Wars Episodes I-VI and The Clone Wars are part of Lucasfilm's new unified canon.
If you didn't read the Expanded Universe, this may not seem like a big deal to you, but it is. The novelizations introduced a number of elements that other books and comics subsequently exploited. Sora Bulq, the Jedi-turned-Sith-acolyte, first appeared in the novelization of Attack of the Clones. The A New Hope novelization said that Owen Lars and Obi-Wan Kenobi were brothers. On a sillier note, the Episode IV novelization also mentioned ducks.
Remember, however, that the canonization of these elements extends only as far as their appearances in the novelizations, so Sora Bulq's activities in the Star Wars: Republic comic are not canon.
UPDATE: Del Rey has clarified their statement about the novelizations to emphasize that any contradictions with the films (i.e. Owen and Obi-Wan being brothers) are not considered canon.