Taken directly from Firstshowing.net : because they have a great record of ALL things Tron Legacy so far:
Holy Crap, Daft Punk is Scoring Disney's Tron 2.0!
Even though Tron 2.0 isn't slated to hit theaters until 2011, we keep hearing big updates on the project, surrounding everything from the plot to CGI cloning of Jeff Bridges. But here's an announcement that I am truly giddy about reporting. The always reliable Upcoming Film Scores blog is claiming that Daft Punk has signed on to do the score for Tron 2.0! They say that Disney has actually confirmed this with them, which means I'm also going to say that it's accurate until proven otherwise. And let me be the first to say, this could be absolutely unbelievably phenomenal, but that may be because I'm such a big fan of Daft
While their songs have been used in plenty of movies, Daft Punk has never actually scored an entire movie before. They did provide almost all of the music for the Interstella 5555 anime, and they did also direct a movie called Electroma, but that didn't feature any of their music. I have no clue how this will turn out, but that doesn't matter, because this could be the greatest Tron 2.0 news I've ever heard. If there was anyone that I could've dreamed about being involved with the music for Tron, it would've been Daft Punk, that is for sure! And lo and behold, they're actually scoring the movie. Damnit, 2011 can't get here soon enough!