Sun and Moon always makes me thing of the tarot cards of the same name, lol.
I always had this feeling that X and Y were just testing the waters for the 3d transition so hopefully they push the proverbial boat out in this case.
Here i'll post some of my dreams for this game;
I was talking about this in reddit but I need a prankster quiver dance user.
More kawaii desu girls clearly
A plot that I couldn't totally predict (like you see Lysandre in the damm cafe where team flare meets up, and you don't get suspicious?)
Return of character customisation (as in, its here to stay)
I can say that there are certainly going to be new megas, but hopefully they aren't just op or silly
Good music (this sounds a bit iffy, but people praise Wally's battle theme so much when its one minute of hardly differing music)