If you don't mind spoiling the events of the Scott Pilgrim storyline before the movie (keeping in mind that it's all based on existing comics), you'll be able to play out the story in sprite-based brawler form three days before the movie hits.

At the Ubisoft booth displaying Scott Pilgrim vs. the World (look for our impressions soon!), an August 10 release date was posted next to the game demo. It's a timed exclusive for PSN, so you'll have to endure an unspecified number of (evil) days before you can take on Ramona's evil exes.