More information about the map editor have been revealed on IncGamers.
Patrick Redding (Game Designer and Narrative Director) and Louis-Pierre Pharand (Producer) talk to IncGamers about the games incredibly versatile map editor, as well as the tools available to players.
Still, being a SC fanatic, I am probably only going to make SC2 maps when it comes out ;)
Awesome! I love it when they allow that sort of development, like SC1!