Well, the docs are a little out of date but most of it works as it did before. I had about 3 lines to change when I started using the webgl version. (details of what needs change is available here: http://code.google.com/p/o3d/wiki/GettingStarted)

Some parts are not yet implemented but I've managed to get work done without using any of them. The core devs are often on the mailinglist: http://groups.google.com/group/o3d-discuss

The repos are active, last update was last week. I just use whatever they have in SVN right now, the packages on their webstite is very outdated.