Unfortunately for those hopes, Square Enix said that the effort is being limited to the website and not extended to the game itself:
We decided to localize the free trial website into Spanish and Portuguese in an effort to lower the barrier to entry for users in Latin America who may be interested in trying out the Final Fantasy XIVÂ free trial. Localizing the website offers those users an easier way to learn about the story, world, game features, and gives them a clearer understanding on getting started in the game. We do not currently have any plans to localize the game into Spanish or Portuguese at this time.
Source: Gamer Escape
