The "Darth" title.
References to any Darths other than Vader.
Two-dimensional villains who are evil for the sake of being evil.
KISS reject darksiders.
Sith in general.
References/allusions to specific events and characters from the PT.
Brown desert hermit Jedi robes.
Leia wielding any lightsaber that isn't red.
PT-styled lightsaber duels.
Hayden as Anakin's ghost.
Further universe shrinkage.