Quote Originally Posted by Ultimate Cloud View Post
Well from what I saw there was roxas in it and plus I think I read the fact that it was the hidden trailer for kh3
As the video can easily be placed as occuring some time before the events of Kingdom Hearts (perhaps before Sora was even born), it is very easy to deduce that the character shown in the trailer is not Roxas. Chalk it up to all of Nomura's characters starting to look like each other as series go on.

Also, as said, there is no such thing as Kingdom Hearts III. Nomura made a point of saying calling the next game a new series. I wouldn't go as far as saying it'll get a name other than Kingdom Hearts, but it's quite possible.