I doubt this is true, but here it is.

Next STAR WARS Title Is?
Could the name for the last STAR WARS prequel be EPISODE III – REVENGE OF THE SITH!?! We are if we’re to go by a reader on Supposedly he knows someone (one of them stories) who works at the domain registrar They told him that Lucasfilm Ltd got to purchase the name for them. Only the force knows if this is true though!