WebGL 1.0 has been finalized and now we can start making use of it, but first perhaps we should evaluate the state of play. After all IE9 doesn't support it and Microsoft doesn't seem to have any plans to do so.
Just a short time ago the idea of full 3D graphics in a web page would have seemed crazy. The rise of the GPU has allowed this to happen but it wouldn't be possible without a standard API to work to and this is, of course, WebGL.
A set of conformance tests are alwo available to make sure that browser manufacturers get it right. Of course the one browser manufacturer not needing to check compatibility is Microsoft. Internet Explorer 9 doesn't support WebGL and the reason is, of course, that Microsoft favours DirectX as a 3D framework. There is a Google project to allow Windows users to run WebGL content by the remarkable trick of translating OpenGL ES 2 calls to DirectX 9 calls. Of course a much better solution would be for Microsoft to get on board and support WebGL.
Without IE support WebGL is probably dead in the water - but it is such a compelling technology that pressure to use it might become a disadvantage to future versions of IE.
Getting started with WebGL
WebGL made easier with PhiloGL