I have created a first cut at a 3D renderer extension that wraps Three.js and uses WebGL.
Those familiar with WPF Viewport3D will see that the models and camera classes are designed using the same class structure and conventions as that library ( Model3DGroup, MeshGeometry3D, DiffuseMaterial, GeometryModel3D, etc. ) so existing Viewport3D code should port with relative ease.
You can download the source and some examples here....
This is an absolutely minimal implementation. If anyone is interested in helping flesh it out please feel free.