I'd like to say that it's absolutely crucial component if making GH as more powerful as scripting. Obviously GH will be supposed to even perform much better because you donot have to know about calculus. Can't wait!
Ideally I'd like to supply geometry as an argument for a function component (which would extract the functions of the supplied geometry as inputs) with derivative or integrals available in the expression editor.
That would open up a whole new world of possibilities to use GH without scripting!