Only major catch is that this would be an easy out for those suspected for RMT. People would be claiming that hundreds of thousands of Gil sent to them by another player was won via gambling (whether it be who caught the most Raincallers during a single storm or who was able to find some random named character first). It'd really just be more trouble than its worth for SE.

I recall some mention of a Golden Saucer during a live chat this summer. I, for one, am looking forward to such content for my gambling fix. Although, it maybe quite sometime before we see anything like it with the current content progression. There's no reason it couldn't be added, but it would likely have automated odds of winning (Chocobo racing anyone?)