Update: It's pretty certain now that this is a type of card game and will be called "Dragon World Challgenge" (DWC). DWC will also feature its own special time machine quests which you can read a bit more about here.
New to the test server files are what appear to be playing cards. There's 4 color variations of almost all of these cards: yellow, red, blue and green and a special purple version of Goku and Vegeta.
I've never been that fond of card games myself, but I remember they were implemented rather nicely in a Lunar game I played once. Perhaps they're used similarly, as temporary buffs? Also, major props to the Bear with a Sword for beating out Farmer with a Shotgun to get on a card. ;)
Got a little something to add to this. There's a few string variables that I've managed to come across that call the card game "DWC" or "Dragon World Challenge" (mentioned before here: http://www.dbocom.com/forum/showthread.php?t=4389). It's also looking even more like it is going to be a card game, but probably not a very complex one.
What do you guys think? I hope these cards give us something to do other than Grind and TMQ and Pray for C.C. DUN. If it was anything like a card game that would be so awesome. Thoughts?