Since Rhino V6 seems to get a SubD toolset, I have the following request:
Adding a Polypen similar to the one in Cinema 4d
i.e. having a modifing tool (gumball) that automatically detects a vertex, edge or polygon by simply mouseing over the geometry. This way you wont need to toggle between vertex-mode, edge-mode or polygon-mode, which only allows to modify one of each at a time.
An autoweld/snapping option would also be extremly nice. Thats means if you drag a vertex or edge close enough the next vertex or edge, they automatically snap and weld, which is extremly usefull and helps avoiding naked edges.