You know what I really want to see in X & Y? The ability to go back to previous regions and start the journey all over again (like in the second generation). I want to be able to travel to previous regions and fight the older gym leaders who have the new Pokémon and features added to them. I think that'd be pretty cool, but I don't see it being added.
That'd be interesting, but I feel that light types would be too similar to normal types. I want to see something unique. There's not too much they can introduce, though, as in not too much room to create new types. People have been speculating that they'll add like a rainbow type, but that doesn't even make sense, lol.