Updated as of 6/10/10:

Fort Mill
Clover
Northwestern
Lexington
Ashley Ridge
Westside
Hilton Head Island - tentative
Stratford Academy (GA)

Olympic (NC)
Porter Ridge (NC)
Charlotte Catholic (NC)
Lake Norman (NC)
Crest (NC)
Forsyth Country Day (NC)
Weddington (NC)
South Mecklenburg (NC)
Marvin Ridge (NC)
First Presbyterian Day (GA) - tentative
Blythewood - tentative

Kids play sports because they find it fun. Eliminate the fun and soon you eliminate the kid.