I know we have stuff like PokePark for the Wii etc but I've always wondered why haven't they brought a Pokemon game out like black / white / red / yellow etc. You know the one where you have to go around getting all the badges, trading Pokemon and eventually getting in to the Pokemon league?

I know they bring it out on the DS but it would be ultimately cool if they brought it out on the Wii. Is there any reason why they haven't?