There's so much to do with the franchise and look at how all the untapped potentials are wasted under Gfreak for freaking more than 10 years.
They could, you know, try something new for once to give us a new experience aside from the outdated formulaes (turn based battles, collect 8 gym badges, etc) With so many Pokemon available, they can easily have a new game with a world of just Pokemon, no humans, with fantastic stories and dungeon crawling with you playing as Pokemon characters talking to each other. Heck, the possibilities are endless. How about a new adventure system where you still play as humans, but don't actually own any Pokemon. Maybe there's a new capture system where you draw circles on the touch screen to get Pokemon or something. As i'm typing this, yet another idea popped up. How about genre change to an SRPG Pokemon game? A game where the humans fight along as warlords and warriors? And oh, while we're at it a card game may work too. Would even milk collector fans more