Well, it's true that the toolbar doesn't help that much. For example, I never really tried to add a combobox to a toolbar, but I don't think it was supported. It probably only supports command buttons.
On the other hand, what would really be helpful and very tied to ESRI's map functionality is to have those buttons show up as pressed-down when the tool is active and if I pick another tool from pressing other button, the former button gets back to not-pressed state. This would require closer handling of what Draw object is currently active in the map. It would work even if I have different toolbars.
Wish list? Or does anyone know of something close to it?