The prospects for what the rover could find has many in the space community very excited, even though Curiosity is supposed to look for habitable environments, not life itself.
However, a couple of weeks ago, noted theoretical physicist Lawrence Krauss said he wouldn't be surprised if we do find evidence of life on Mars.
In an interview with CNN (below), Krauss said it's possible Martian life could have "polluted" Earth early in our planet's history, giving rise to life as we know it today.