I would add an “Edge approximation” tool similar to what’s available in VSR for Rhino 5. In essence, it re-trims a selected trimmed surface edge do user-set value to make it less dense, resulting in a much simpler adjacent surface that matches to this particular trimmed edge (or an extrusion built from the latter).
Also, a better “Blend surface”, as mentioned by a few people above. I already started a topic for this here:
Skew surface, proposed by @eobet , is yet another useful tool that was also shown in the video @thomas_parel posted above regarding the VSR tool:
Arrows for a direct control point manipulation similar to what Alias has. This is an extremely important tool that I’m sure will make the life of many modelers easier:
Light lines that we discussed many times recently, would be also a welcome improvement for the current Zebra analysis tool.