I just received the following information from Erin Wood at NGS:
The National Genealogical Society is pleased to announce attendance of 2,270 at the NGS 2011 Family History Conference held in Charleston, South Carolina, 11-14 May.
Over 1,500 people purchased a full conference registration and over one hundred people purchased a daily registration. In addition, conference attendance included speakers, vendors and their booth staff, and many volunteers provided by the South Carolina Genealogical Society and its local chapters.
On Saturday, Ancestry.com sponsored an Ancestry Day program which brought an additional 575 people to the convention center. Over 2,000 meals were served at the local convention center and social events sponsored by the South Carolina Genealogical Society, providing genealogists many opportunities to share stories about their research and their ancestors.
The NGS 2012 Family History Conference will be 9-12 May 2012 at the Duke Energy Convention Center in Cincinnati, Ohio. The conference hotel is the Hyatt Regency Cincinnati, 151 W. Fifth St., Cincinnati, OH 45202. Conference registration will open 1 December 2011.