Judging from Panda's pics, the point is the new Rider pose I guess.
Mayhaps he'll get a phrase to go along with it.
EDIT: Also sounds like we're getting a third voice for Double, and not a mix, unless the voice in that video is a placeholder. He clearly says "My name is Kamen Rider Double" and it's not in either of their voices. And he uses a first-person singular pronoun.
On the bright side, Kiriyama has a nice voice and is apparently 24, so he's a bit older than some of the ones we've had lately. Suda on the other hand is 16.