"I can confirm that Final Fantasy III contains Wi-Fi, but I can't reveal the details at this time."
That's the line a Square Enix spokesperson provided to IGN when they asked them about a leaked image that found its way onto Go Nintendo. So, the obvious idea is that there will be some sort of co-op gameplay and trading, whether it be items or chocobo (chocobii?). Given that, what other ways could Square Enix implement Wi-Fi into the game? Never having released stateside (our Final Fantasy 3 on the SNES was Final Fantasy 6 in Japan), I have no frame of reference for the game on a whole, unable to decide in which ways Wi-Fi would or could enhance it.