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.

H/T TaxprofBlog