Maybe we can replace the Pokémon Center in Goldenrod City with the Pokémon Communication Center from the Japanese version of Crystal. More information on the building itself here: http://bulbapedia.bulbagarden.net/wiki/Pokémon_Communication_Center. Maybe we can retain the news station for local news that may be sent out for Pokémon 3D in general. The GS event can occur here, giving players a chance to capture Celebi in Pokémon 3D. Maybe even in the far future, we can battle/trade with people worldwide, as the Pokémon Communication Center did, just without those mobile adapters and all of that junk.
Image of the city with the building visible:
Image of the city with the building visible: