Tim Merrit's had some good material recently. Generally speaking many people are saying that it's largely symbolic, but that's the point. It's very clear that the value that MIT brings to the table is what happens in their classrooms. There's some correspondence I'd like to quote from, but I'm waiting on permission first. The 3.2 version claims AICC and IMS conformance.
Users can zoom in and virtually cut open different membranes to further investigate the cells.
Other interesting items at Wired as well. It is a spin-off from the Conzilla project. Some folks provided libraries that made Navigator act as much like IE as possible. Others provided libraries that made IE act as much like Navigator as possible. I suppose many of us did back then, but I burned out on betas long ago.