This is very much a work in progress, over the coming year. Right now we are working on the boring nuts and bolts stuff. Currently, we have sky, terrain, water, chat and very crude avatar movement..
Or.. if you would like to play with the Scene Editor. It can be found at hgility.com/3j/live/editor/
Click on some of the examples, listed on the left. Or to see a complete collection of demos visit threejs.org/examples/