Even though it isnt really “planned”, they want to give the people the chance of making a Starcraft 2 DotA map or minigame if you so will. As to the first DotA it will be up to the community to create and make it happen. It seems as the game editor will make it possible, with a chance to make equipable characters and so on. Anyway. Yes there will be a Starcraft 2 DotA, I would be in shock if nothing like it was created.
For the whole video about it: http://www.starcraftzine.com/2008/10/starcraft-2-dota/
@Start And Select