Microsoft seems quite reluctant to implement WebGL in IE, since OpenGL is a competitor to DirectX. So I think it's unlikely we'll see WebGL in IE in the near future.
I’ve started an Open Source project called JebGL that can serve as a fallback for IE users. It’s a Java applet that when finished will serve as a plugin replacement for a WebGL canvas. It’s still in the early stages of development, but you can check out the demos at http://jebgl.googlecode.com
