well considering Sidious' entire plot and scheming has been to get revenge against the Jedi for what they've done to the Sith (well deserved by the way), and the way titles have been similar in 1-4, 2-4, it would make sense that it would be something along the lines or ROJ, and combined with the fact that we know GL was going to try Revenge of the Jedi, Revenge of the Sith or Rise of the Sith would definetly fit. I like the Revenge one better, its not so clean and plain.