Oh boy... So S/M and US/UM to me represent the first actual downgrade for the series and I hope that Gen 8 is only like them in that it is a "traditional" Pokemon game unlike LGP/LGE. Here's a few things I'd like from Gen 8.
- Less useless features. S/M has a pathetic excuse for a Pokemon Snap addition, Pokemon Pelago is an utter waste of time, the Pokemon tree house thing was an inferior alternative to the battle factory - if it introduces new features, then I hope they are considerably more thoughtful. Similar features to what was in S/M could have worked but were poorly executed.
- More overall customization. Trainer customization was a fun thing and I hope it comes back with more detail. As far as Pokemon, I think they can make things easier on the competitive side and even aesthetically, for example like picking the Pokeball for your Pokemon without necessarily using it to capture the Pokemon. I don't see why any Pokemon I capture has to be doomed by inherent traits such as a bad nature - just let the trainer be able to tailor their Pokemon to its full potential.
- Multiple challenge levels. Pokemon has a wide audience and it deserves to have varying degrees of difficulty for the main story mode. BW2 knew what was up.
- Attractive online hub. 6th gen got this right, 7th gen was a complete reversion.
- More interactivity with Pokemon. LGP/LGE bringing back following Pokemon and allowing you to ride your own Pokemon is great. Amie was somewhat fun. I'd love features like this to be introduced because it makes everything more personal.
- I'd like the game to honor all the past generations without a lot of bias while introducing the new. Perhaps in a similar way to gen 6, with less bias toward the 1st generation. Maybe this is unlikely, but I don't like a heavy lean on new things or towards gen 1 in particular.
- Be done with the second game bullshit. I don't want BW2, I don't want Platinum/Emerald/etc., it's a new age and it's time to just go with DLC content. I'd pay for it even. I don't want a secondary game which is basically the same thing but with some new features to be released. Just go with DLC so that I can continue off the save file I put so much time and effort into (and not have to pay for a new game). I am not arguing against a 2 game release such as Red/Blue, this is a series staple and it is fine.
I don't know what to expect with these games but they have been in development for a long time, and with LGP/LGE appealing to the new crowd and long time no see crowd, I think the experienced player crowd is going to receive more attention this time around. I'm cautiously optimistic that whatever comes out is going to be satisfying.