Original: It was released in North America on May 23, 2010, in Japan on May 27, 2010, in Europe on June 11, 2010, and in Australia on July 1, 2010.
Simplified: It was first announced at E3 2009, and was released in the second quarter of 2010 in Japan, on May 23, 2010 in North America, on June 11, 2010 in Europe, and in June-August, 2010 in Australia.