The original was groundbreaking in its CGI (probably didin't even have the term CGI at the time) and was a great influence on my generation getting hooked on computers. Keep in mind that this came out before War Games. Go back and watch TRON again, and you'll clearly see a number of themes that seem original today yet were tackled in a movie released almost 30 years ago.
Get the skinny and see the trailer here from IMDb's Holiday Movie Guide:
http://www.imdb.com/features/holidaymov ... tronlegacy
And the details here:
Or pay homage to the mouse and go to the official site: