There's definately not going to be a new type. I've been with Pokemon long enough to remember Gold/Silver/Crystal, and play the remakes of Red and Blue, and have played very region. I know the style of the creators, there will be some new items, moves, pokemon (obviously) and some sort of new map theme. I'm very confident, however, they will keep to the original 16 types.
On an off-note, I think ever since the GBA the move's animations have gotten worse, not graphically, but in the sense they don't look as cool as they used to (IE flamethrower, dragon claw).
Why is it called 'common sense' when it is so rare these days?