Pokemon has conquered the WiiWare space already with many releases that have hit Japan and are coming North America and Europe as well eventually. Other then Pokemon Battle Revolution, Pokemon has shyed away from retail releases on Wii. It looks like Nintendo plans to change that though with a new retail release for Wii.
The Trademark “PokePark Wii Pikachu’s Great Adventure” was listed for Wii in Japan. While this could have just been another WiiWare title, amazon.co.jp has listed the title as well. One could assume based off that it is indeed a retail release for Wii.( I don’t believe Amazon in Japan sells WiiWare titles on their website like Amazon does in North America)
Other then that no details were released