Yesterday, we reported Nintendo had set a release date of January 9, 2006 for Electroplankton, based on the game's page at Nintendo.com. Other news outlets noticed this at the time.
However, since then, the date was removed; the game's release date has since been returned to its previous state of "Announced".
While we can still expect Nintendo will bring the title outside of Japan's borders sometime, it seems that as of right now, they're not letting us know when. Stay tuned for any further developments.