There are a number of MMO titles coming to PS3 via Sony Online Entertainment. This ten minute video from the developers tries to explain how the upcoming casual MMO will work, starting from its Facebook-like social networking website, moving on to the four styles of gameplay Free Realms features. Burning questions like "can I be a ninja?" are answered (the answer is yes). Unlike other MMO games, Free Realms is more about various mini-games -- there is combat, but it's optional.
If this piques your interest, you may want to check out all of Massively's coverage so far.