The only thing I didn't like was Vanitas's laugh. It wasn't creepy/batshit insane enough for me. Then again, I guess I shouldn't be comparing it to the Japanese version - now THAT laugh could give you nightmares.
I think for the most part the cast improved though, especially Aqua - I was glad to hear more from her. And I LOVED Terra and Ven. Eraqus sounded good too, and so did MX, IMO.
I was so excited to hear Quinton Flynn do a younger voice, and I think he pulled it off (not going to make any final judgments until the game, mind). Isa sounded okay too. I loved hearing the other apprentices - totally looking forward to hearing more dialogue, especially from Braig very psyched about the secret ending in that regard, too.
Also, just one more thing I didn't really like about the trailer was the music. I think it was a little too loud.
MX suddenly sounded like he sucked on helium I just got an image in my head of him doing that. Now I'll never be able to take him seriously. LOL