This site is very useful. My teaching methods students designed a lesson around the Billy Joel song, We Didnt Start the Fire. Feedback was very favorable from the students. They all were able to articulate specific historical events or identify people they had not been familiar with. I would encourage use of this site. The students claimed that the site was very valuable to their learning experience.
They claimed that some links were either broken or not helpful, but they didn't seem to think those problems were devastating.