A few things you should keep in mind before watching it:
1. this movie was produced by Disney, so obviously they had to make everything 'kid friendly' and relatable to a young audience. If this movie was made for adults, it would have an R rating and probably be the best movie of 2010, especially if you had Christopher Nolan and Aaron Sorkin on the project. Disney ALWAYS has to mess things up (with an exception to the Lion King, Toy Story, and Aladdin...and maybe even Wall-E...on second thought, the Disney parks in Orlando, FL are pretty dope. I will table this for later.).
2. Cliche dialog to the maximum. There isn't a single line you couldn't predict. The character interactions reminded me of the movie A Goofy Movie. (I am not gonna lie, I cried in A Goofy Movie...but then again I was like 6 years old)
3. For the most part, the casting was poorly done, and the characters are so outlandish (e.g., Michael Sheen's character). The good part is, Daft Punk makes a cameo. But deep dialog and developed characters is not the goal of this movie. For some reason, all the women in the movie were oddly attractive (e.g., Olivia Wilde).
4. There is way too many themes going on in this film, and fairly overtly. To name a few: Good v. Evil, Jesus, perfection, greed, identity, technology, futurism, etc. My favorite was transhumanism.
Why Watch It?: I thought this film was better than Avatar. You felt like you were actually IN the game; straight up light and music show. Daft Punk created the soundtrack for the movie; their music was the movie. The visuals were amazing, I would love to watch this movie again on Blu-ray with a Bose sound system. Think of Tron as a two hour long Daft Punk music video. With that mindset, you will appreciate it that much more. Remember to watch it in IMAX 3D, and be sure to be seated directly in the dead center of the theater.