From Corocoro, the new Gamecube Pokemon related game, if you could call it a game, is known as Pokemon Box. It will be released on 30th May in Japan. From the name and the descriptions, I don't think it's any R/S stadium but rather a useless package that allows you to store up to 1500 pokemons in the system (R/S can store up to 520 I think) and let you show off on some screens or whatever. It has no words on getting the unobtainables but I think it would feature this otherwise nobody would really buy this considering its gameless feature so far.

I hope the next Corocoro would reveal more attractive features of this game otherwise I don't think it will sell well.