I would LOVE another Stadium or Colosseum game. They're my favorite spin offs and I would love to see another implement of Cipher and Shadow Pokemon. I hope the plot is more dark like Colosseum instead of lighthearted and...whatever XD was. But I'm not here to discuss that game! Anyway, if not a Colosseum follow through, then I'd love to see another Stadium with Doduo/drio Towers, mini games, gym leader castles (that'd be one big castle with five generations!) and of course, the stadium. Plus with online play, that'd make it better. But I do not want to see a PBR ever again. I don't like it. It doesn't compare to Stadium or Colosseum.
A few things I'm wary of though.
- Move animation. In the Stadium games, it looked like it actually hurt, such as Rollout actually flattening the opponent, and it looked good and even gave a slightly comedic effect. With gen III and on, the moves looked progressively weaker (technically, this goes for 3D and handheld games).
- Rental Pokemon. I don't mind the rentals from Stadium, but a little more customization would be cool. Not right off the bat, though. Maybe after meeting a certain criteria in gym leader castle or the stadium, you can be allowed to customize the moves and natures of rental Pokemon. Similar to making your teams on Shoddy, maybe? I don't know. Either way, I'm always good with rentals. This isn't too much of a problem like the one I mentioned before.