There has been some info on the chocobos.

In towns, you can rent them for a limited period of time. So, after that time period, the chocobo you rented will be gone. You can also see chocobos at places outside of towns. If you find an untamed chocobo, you just have to feed them Gysahl Greens to ride them. I'm not sure if there is also a time limit to untamed chocobos. Also, there seems to be a Turbo command to make your chocobo run faster. That is all what I know right now.