nope There are ten challenges, varying in duration, to suit the amount of time you will be dedicating to Rock Band 3 in a single sitting. Some may last three hours, while others can be completed in a half-hour. There are suggested setlists for each challenge from the Rock Band 3 on-disc library, but players can create custom setlists along particular themes (genre, band, etc.).
Within each challenge, players can earn bonuses based upon several new scoring mechanics. One awards note streaks, while another awards deploying Overdrive as many times as possible in a single song. The full list and much more information can be found at the Rock Band Zine.
Rock Band 3 ships on October 26 for the PS3, Xbox 360, and Wii. A DS port is also in the works, but won't be the same experience, obviously.