Cathy's team has just released their Canvas3D js lib C3DL version 0.6. The library is starting to be capable of doing some cool things (Collada support, picking, particle system, textures, etc.), and has attracted a number of external contributors (ya open source research!). Ted wrote a cool panorama image demo using it, too. If you're interested in 3D in the browser, check out there work and get involved. C3DL is MIT licensed.