The timeline shows the top 1,000 people in WorldCat Identities (by number of library holdings) plotted according to the first date that Identities has associated with each name. Sometimes that is a birth date, other times just the first publication date associated with them. It always seems to be the case that whenever you display information in a new way, anomalies in the data that were hidden now become apparent. I've noticed a few in the timeline, but will resist the urge to point them out here. Incorporating more of the information from the Virtual International Authority File would help, since it has more complete date information.
Scaling this up to handling more than a thousand Identities looks difficult. Even at this size the scrolling is uneven on many workstations, and more names make the problem worse. My original hope was to have tens of thousands of names, but that doesn't seem practical right now.