[mbostock]

Yes, in a variety of ways. All marks currently support native tooltips (the title channel), and in the near future we’ll be releasing more interactions that you can compose into the chart, e.g. for brushing or pointing. As I mentioned in another comment here, Plot is designed to leverage Observable’s language-level interactivity (dataflow) — so all plots are reactive by default, and plots can expose an interactive selection to the rest of the notebook.