I'm thinking storyboard artists for 3D animated movies would love this.
Consider that artists have already become experts at sketching, at visual design, etc. For them, a pen or stylus or 3d program doesn't feel like tooling, but give them an unfamiliar tool and it will totally get in the way of creative expression.
The question to me is whether Vim3D is actually bringing significant improvement over whatever shortcuts exist in current 3d modeling software.