First of all I'd like to point that this is an article released by FighterForum.com and Fomos.kr. It has not been confirmed from the blizzard websites yet (as far as I know).
 
http://www.fighterforum.com/news/n [...] &idx=23976
http://www.fomos.kr/board/board.ph [...] eld=&kwrd=
 
Blizzard Entertainment will hold a press release/preview that announces the third and final race, zerg in Korea. On the 10th of next month (March 10th) the event will be held at the Grand Intercontinental Hotel Ballroom to unveil the final race of StarCraft 2, Zerg. Frank Pearce, the vice-president of Blizzard Entertainment will be attending the event.
 
Additionally, a demo station will be set up that will include all three races of StarCraft 2 for hands-on gameplay.