Dooku's defeat
In 2005 when Episode III hit the screen, we saw Anakin and Obi-Wan fight Dooku and Anakin defeated him. It implied that Anakin's skills had increased so much over the three years that he was able to kill Dooku. Yet in Clone Wars, as late as Season 6, Dooku was picking the two apart on Oba Diah. Is it possible that his lifeforce being drained by Talzin and whatever happens in the Ventress novel, weakened him so that he was defeated.