The latest buzz around Star Wars: Rebels is about who will score the theme song of the new TV series. There are three reports so far and three possibilities. I doubt there is anyone who would be disappointed if they choose one over the other from the above names. So whoever it is, we're fine...
So first according to MakingStarWars:
John Williams is writing the new Star Wars Cartoon’s theme song. Part of the deal that brought Williams back to Star Wars also brought him on to do the themes of two television projects for Lucasfilm.
The theme is a new theme, not the traditional Star Wars theme we all know or piece reworked like The Clone Wars had.
Later another source by the same site suggested that:
Michael Giacchino was considered. No one is officially on Star Wars Rebels yet.
Michael Giacchino was firs expected to score Episode 7 and giving him to make the theme song for Rebels looks like a logical move. Especially considering his relationship with J.J. Abrams and their previous projects.
JediNews also shared their input on the story. According to them John Williams was not only contracted to write the score for Episode 7, 8 and 9 but also two television projects, one of which being Rebels.
Also their source Jedi Master SQL made the situation even more complicated:
Williams is on board only for the Sequel trilogy, but I understand another possible composer could be in line for the Rebels theme - J.J. Abrams himself. Abrams wrote the themes for Felicity, Alias, Lost and Fringe and according to my information he could possibly involve himself in the show in that way.
So whoever they choose the outcome could be only one - another memorable theme for the fans to enjoy.