UPDATE - The info we had up was apparently false, but now we have the full details from our friends at Serebii...

Info comes from the latest issue of Coro Coro...

New female character
Opposite gender character will help you in your quest
3d images as you enter a new area
The Pikachu Coloured Pichu, which is given away with the 12th movie, activates a special event in Ilex Forest when traded over from Diamond, Pearl & Platinum