The Harvard Crimson says that there was an apparent increase in applicant diversity compared with 2011: 39 percent increase in requests for application fee waivers (which can mean more low- and middle-income applicants applied), 22 percent in the number of African-American applicants, and 24 percent in that of Native Americans.
The Crimson points out that Harvard intentionally "discontinued the early action program in 2006" partly because of the issue of inequality: "early action is often thought to favor students from privileged backgrounds who have the resources to get ahead start on the college application process." Therefore, the increase in applicant diversity is a "good news" for Harvard (as the newspaper calls it), and Harvard now has a good reason to continue the early action program.
From: "Progress in Early Action: Harvard's Doing a Good Job Playing a Bad Game," The Harvard Crimson, Dec 07 2012. http://www.thecrimson.com/article/2012/12/7/progress-early-action/.