We should be used to this by now...it's classic Square-Enix 'we announce shit way too early' syndrome. They generate interest by showing off trailers and wonderful screens of what has been completed, even if the game is 1% into development, which is bullshit if you ask me. It's like a cry for attention:
"Hey, we're Square-Enix! Remember us? Here's a trailer for a game that won't be released for another 3 or 4 years!"