I found this article on the Moodys Tax Weekly:
It seems to me that any effective, responsible retirement / estate planning, leaving something behind for our families, can drastically change when taking into account US citizenship-based taxation, excessive penalties (vs actual taxes owed to the US). If we have been able to do any careful planning with our countries’ savings incentives (such as Canada’s RRSPs, RRIFs, TFSAs, RDSPs), certain mutual fund investments, etc. it all now has a different face. Some are already there, into retirement, out of the work force and with limited choices to change course.