In response to this Stack Overflow question I thought it would be helpful to demonstrate one way to add vertical lines and labels to a nvd3 time series lineWithFocusChart. Hopefully it will help both the R rCharts and the straight Javascript nvd3 user. I solved a small syncing problem with the brushing by adding a window.setTimeout on brushend. It seems to work fairly well.
Please let me know if there might be a better way to handle.