I spent an hour browsing the site. I looked at some exhibits (Devices of Wonder, in particular), some of the Lesson Plans, and a brief look at ArtEdNet Talk (threaded discussion). The quality of the content is amazing! Great use of animation, video, graphics. Very easy to use, even for first timers. I think this is an excellent resource for teaching and learning. The interactivity promotes active learning, and it was fun!
The only problem I encountered was with Real Player. Although I did have Real Player installed I was prompted to download the latest version (Real One Gold), which still didn't play the video. (RP does work on my system, just not with the Getty content.)