From International Tax Blog:
The number of individuals expatriating from the U.S. more than doubled in 2010. Expatriating individuals include people that either renounce their U.S. citizenship or terminate their long-term U.S. permanent residency.
In 2009, the total number of expatriates was 742. In 2010, the number increased to 1,534 — a 207% increase. Last year had perhaps the highest number of expatriates in any year in U.S. history. I anticipate that this trend will continue.