From October:

Gamer Escape: You’ve said that MMOs are like amusement parks. What kind of other rides do you have in mind for 2.0? Some of the concepts looked like maybe there was something for a chocobo farm or racetrack. I’d love to see something like one of the Final Fantasy card games like Triple Triad be added into the game.

Yoshida: A lot of people on the development team have come to me with ideas for types of card games and even when I was a dev myself, I designed a card game as well but it was very difficult. The biggest thing is that when MMOs players play, they play for rewards and they want really good rewards and so making a good card game system that has a good balance that is difficult enough but that also has really good rewards can almost be as difficult as making a battle system that is balanced and so I’m waiting right now for the perfect plan to come across my desk. They have a lot of ideas but I’m waiting for the perfect one so when the perfect one comes, I’ll OK it. That’s not to say that we’re never gonna have a card game but the ones that have gotten to my desk so far haven’t passed the test.
We'll get one, it's just a matter of time