In my opinion, there are enough of 2d drafting tools out there.
I would rather like to see a continuation of new 3d features that you don't find very many other places, like the silhouette, sweep with scaling rail, N-gon meshing.
A feature I could imagine be useful is a kind of "ridge detector", that would draw a spline on the areas of highest mean curvature.

Se pic of meancurvature from rhino. Here I used Rhinos Meancurvature to find ridges. A feature that could single out convex and concave ridges would be helpful for building models from 3d-scanned objects (meshes). I think it can be useful for planning how to build a nurbs model from a mesh in general. The ridge areas tell you where to start and end fillets ans small blend surfaces that often define edges of objects.
This might be a silly idea, and it may also require a lot of effort to make it work properly, but I think it can be useful.

Will be fun seeing what Michal has up his sleeve. I am at least always surprised by the good features he continuosly adds, - things that just seem natural and simple to use once they are there in that sleek UI,..

-Fredrik