Yes, unfortunately there will be new Pokemon this time around, however the entire game world engine has been revitalized. For years the Pokemon in-game worlds have run with a top-down classic RPG style, by October we will have a more Final Fantasy style 3D game world.
Additionally, the battle engine does not appear to have changed from what little we see in the video, however attack animations are fully 3D and great looking, in my opinion.
http://gematsu.com/2013/01/pokemon-x-and-pokemon-y-announced-for-3ds