The online aspect of the game basically seems to revolve around the versus mode battles from the previous titles and planting them in an online scenario. You've got "pet" and "house" stuff to collect and unlock, you can build your own island (perhaps from the very crap you roll into a ball) and get new clothing along your journey.
Now, you may be wondering, where does the PS3 tie into this? Isn't this about the PlayStation losing another game to a different platform? Not entirely. Apparently, this deal was struck so Namco-Bandai could get their feet wet in the Korean market, where this game is being developed. If you've been paying attention, Namco and Sony have formed Cellius, where "Cellius will use Sony's Cell chip, which powers PlayStation 3, to create games for the console and content for mobile phones and personal computers." Hmm, is anyone else connecting the dots? Sure, the dots aren't clearly black against a white background, but if the public of Japan and America demand it, perhaps this "Cellius" will distribute KDO to the rest of the world. Anyone agree, disagree, want to roll up some suburban neighborhood into a giant ball of doom?