A fight between Revan and Exile would be cool, especially since the two appear to be the "Chosen Ones" (of the period anyway), and since it appears Revan was taken by the dark side by 2, it could be the Chosen One of the Sith vs. Chosen One of the Jedi.
And like I mentioned before, if the two fight, I want Duel of the Fates as the music.
Thing is, where would we have that fight? Tatooine's Dune Sea? Coruscant's Jedi Temple (with the Room of 1000 Fountains and the place where the Jedi Order gather at)? Lok's vicious wasteland (or volcanoes)? Some unheard of planet? Telos? Dathomir? Endor?