Unfortunately, Nintendo never releases Wiiware dates.
But judging from the Japanese release date(Aug 4,2009) I assume they don't plan to translate it seeing how Pokemon Rumble was released 2 months before it(June 16, 2009) and was released in North America(November 16, 2009) 5 month difference. While the mystery dungeon game has been out for 9 months.
Also note the My Pokemon Ranch release dates.
JP:March 25, 2008
NA:June 9, 2008