A lot of us are working on 3D interfaces for design tools, but the difficult part seems to be making it bearable for longer sessions (hours). Some examples:

Medium https://www.oculus.com/medium/

Tilt Brush https://www.tiltbrush.com/

Quill https://www.oculus.com/experiences/rift/1118609381580656/

MARUI https://www.marui-plugin.com/

Simplex http://www.gradientspace.com/simplexvr/

Gravity Sketch https://www.gravitysketch.com/

Unity EditorVR https://blogs.unity3d.com/2016/12/15/editorvr-experimental-b...

Unreal Engine VR Editor https://docs.unrealengine.com/latest/INT/Engine/Editor/VR/

Modbox http://store.steampowered.com/app/414120/

Mindshow http://mindshow.com/

and my own tool Sketchbox http://sketchboxvr.com

So far it seems like the traditional CAD players (Autodesk, Dassault, Adobe) are focused on using VR for visualization, rather than creation.