https://www.youtube.com/watch?v=Z2Xkvrt6JcE

I am still looking for the official trailer. :)

Why have all the Caucasian characters been changed to Asian?

I hope that it turns out good. I'll still watch it most likely.

Here's a vid on a Attack on Titan attraction at universal japan.
https://www.youtube.com/watch?v=qqs9-F4MlI0

It may have been easier to find Asian actors who speak Japanese fluently.

I'm just hating on it because I just hate on all anime based live action movies.  I have rules for proper anime to live action and the rules are simple.  Mirror the anime for every important scene, but do it really well like we'd believe it's happening in the real world.  Just do that, and I won't hate.  Can you name one anime to live action that does that?  No, right?  Well, Rouroni Kenshin is the exception.  Because it follows my rule of absolutely copying the source material, but with believeable human alternatives and killer ass battles. 

I mean really, follow Attack on Titans exactly with importants shots made realistically like the ones in the video and then I won't hate. Make me happy Japanese Hollywood.

I am excited and hope it's good. I'm not sure how well it will work, it really needs a great director like Christopher Nolan, Brian Singer or maybe Ang Lee or Peter Jackson. Somethings don't work as well or the same, and I think it's a mistake to film it in the same way.

I was so disappointing with the live action 'Space BattleShip Yamato' aka Star Blazers in the USA. It was almost unwatchable at times. I hope they don't make something like that. I would be sad.

I like AoT the anime a lot, but this live action movie makes me shake my head.

Look let me explain, the sitting, characters, culture in Attack on Titan gives a European vibe, and so, why the hell is the movie full of Asians? To make matters worst a Japanese actor is playing Eren. The name Eren doesn't sound Japanese to me. This stuff is breakin my immersion!! My immersion!

If AoT had more of an Asian sitting in the anime, then everything would be ok.

Replying just to answer this question.
Yes. They're Asian but are drawn certain ways to appeal to both Asian and Western audiences. The characters in Naruto all have Japanese names as well. Everything from clothing, sittings etc is Asian in Naruto. Killer Bee is an exception.