The candidates have been selected, and their interviews confirm that at least 6 of them are in sororities:
Arkansas: Jessica Furrer -- Alpha Sigma Tau
Colorado: Laura Cisneros -- Sigma Gamma Lambda
Hawaii: Jennifer Furbank -- Delta Gamma I'm pretty sure (she refers to her work for the blind with her sorority while at LMU) -- wish she'd edit out that Benadryl comment, though.
North Carolina: Chelsea Cooley -- Delta Zeta
South Dakota: Jessica Fjerstad -- Kappa Alpha Theta
Wyoming: Abby Norman -- Kappa Kappa Gamma (does she look like Sarah Michelle Gellar or what?)
Some the others look like they might be sorority women, since they've heavily supported charities that our groups are attached to, but only the ones listed above specifically mention their affiliation.
http://www.missusa.com/index2.html