Being able to draw stages is going to make this mode so much better. Not only will it make building faster, but will allow more different kind of designs then ever before. The amount of crazy stuff I'll be able to design now is going to be insane.
Plus I can't wait to see what some of the more artistically creative people will create now since you know there's going to be some artistic masterpieces being made. If some people are able to draw amazing things on Miiverse, I can't wait to see what some of them will create in this mode now.