Well, in terms of rebalancing, not much, at the moment. I still haven’t digested the impact of the changes Game Freak made in X and Y, so I don’t know what needs changing.
If we’re talking about sweeping thematic changes… well, there would probably be two or three fewer types, one way or another. I’d either eliminate Ground or merge it with Rock, call it Earth or something, because really earthquakes have everything to do with rocks and not much to do with soil, and no-one seems to know whether sand powers fall under Ground or Rock, and honestly it all seems a bit arbitrary at times. Maybe shuffle some of them over into Fighting instead while we’re at it. I don’t much like the idea of Normal as a ‘miscellaneous’ type, either, and I sort of think that with Fairy in the mix now you could probably do without it; just toss everything into Dark, Fighting, Ground (or Earth or whatever we’re calling it now) or Fairy. All the birds can be straight Flying, Kangaskhan can be Earth/Fighting, Porygon can be Steel/Fairy, Exploud might have to be Earth/Fairy or something, and Kecleon can be whatever he damn well pleases; you get the idea. Sort some of the Normal attacks into types, and declare anything left over ‘typeless’ – resisted by nothing, strong against nothing, and no-one gets STAB on them.
Pokémaniacal 