I'd really like to see Generation 5 provide some kind of Pokémon Box or My Pokémon Ranch game, or something like Stadium that provides extra storage (well, more than 14 boxes of 20 each ). I've got around 4,000 Pokémon stuck in my Generation 4 games, and almost another 700 in Generation 5, and I'm running low on space to store them.

I'd actually love to see more of these games, just as long as they don't try to go for a complete gimmick. I did enjoy ranch for just the amusement of having a small farm of Pokémon. I would love to see another stadium game. Those where fun. As long as it isn't dependent on your Pokémon. As for the box, I wouldn't mind a storage.

Something like XD or Coliseum would be nice, I loved the story aspect of it in 3D. I mostly would just love battling in an open environment, free like Stadium, but not completely held back like Battle Revolution. And more storage would be nice, I'm actually planning on completing the National Dex in Black 2.

Absolutely yes. A standalone storage game would benefit collectors trying to fill up their Nat. Dex or for those who collect multiples of one Pokemon for competitive battling purposes. I'd like to see a game tailored specifically for shiny-hunters, though; One that could wirelessly connect with BW2 and transfer any eggs in the Day-Care to the other game. Then, factoring in the player's steps in BW2, automatically hatch the eggs in the storage center. Maybe have a feature where, once a shiny is located, notify the player through an on-screen notification and allow them to switch from BW2 to the storage without closing out of the first.
Something like that would make me throw all of my money at Nintendo.

Ya i would like to see something like this, i never played any of stadium games but the very first one. I have the gamecube collisum game but not XD.

I enjoyed Stadium one and two. It had enough content to make things interesting wherever you went. I wouldn't mind a 5th Gen Stadium game AS LONG AS it's not just a 5th Gen version of Pokémon Battle Revolution.

A 5th gen Pokemon Colosseum would be very interesting and I'd love to see one being made for the Wii/WiiU. Perhaps there could be such a game like that with a storage feature added, so that people can have extra space to store their own Pokemon with easy access.
I don't know if this is a crazy thought, but I can envision there being a Shadow Genesect, as if it was programmed to be initially a shadow Pokemon.

Another stadium game would be nice. On the Pokedex 3D they have some nice models and animations already set up, so heck, it might not be too far away.

With 649 I have to keep in a limited amount of boxes I really need a place to store extra pokemon.

As for a 3D game, PBR was a disappointment to me, I would much rather see another game like XD but it's highly unlikely to happen now.