Appleinsider has posted a quicktime version of the Pepsi iTunes Superbowl ad.
The ad was described earlier today by Apple:
This groundbreaking ad, featuring 16 real-life teenagers who were sued by the recording industry for illegally downloading music from the Internet, shows music fans a new way to freely and legally download music--the Pepsi iTunes 100 Million Song Giveaway. The commercial is set to Green Day's version of "I Fought the Law.
Update: MacCentral links to another copy of the ad.
Alternative Link #2: Pepsi iTunes Ad (thanks CodeRed)
Alternative Link #3: Pepsi iTunes Ad (Thanks appleguru)
Alternative Link #4: Pepsi iTunes Ad