I’ve been working on LookingGlass which is a stand-alone, you-have-to-download-it viewer for the OpenSimulator virtual worlds. I really wish one didn’t have to download the viewer. Viewing should just happen as part of the web.
I’ve looked at this several times and it looks like the infrastructure is maturing. WebGL is appearing or will soon appear in most browsers. This provides the basis for getting accelerated, 3D graphics on the screen. Additionally, it is standard in the browsers (IE is a problem, Microsoft being who they are, but Google has a plugin to fix that).
Recently, Google has decided to move their O3D project to being a scene graph wrapper for WebGL. This makes JavaScript connect to the 3D world reasonably while keeping all the 3D technology in the standard browser.
The new O3D is early in its development but it is coming. 3D on the web is just around the corner.