I'm fine with the combat system staying as it is, mechanically. What I want to see is faster and more streamlined combat message processing (or an option for it), not needing to press A to confirm basic messages all the time. I want animations for everything in combat to be sped up. For a game that has such a huge emphasis on grinding for levels, Pokémon sure is a slow game, and it's only gotten slower with the newer games. I don't want to have to turn off animations because I like my visuals, but there really needs to be an option to play sped up skill animations (2x, 3x faster).
I'll be happy if they can speed up battles by a good amount, even if they keep the mechanics the same.