Molecular archaeologist Christina Warinner gave a TED talk and the main ideas are now in a CNN article: "Why your dental plaque is valuable".
By applying advanced DNA sequencing and protein mass spectrometry technologies to ancient dental calculus, we can begin to reconstruct a detailed picture of the dynamic interplay between diet, infection and immunity that occurred thousands of years ago. This allows us to investigate the long-term evolutionary history of human health and disease, right down to the genetic code of individual pathogens, and it can teach us about how pathogens evolve and why they continue to make us sick.
This is really neat work, although the article doesn't go into any new results.