While the validity of marriage equality in Indiana still hangs in the balance as the Seventh Circuit of Appeals deliberates, the marriage licenses that were obtained during the window of opportunity are still valid.
According to information provided by the state and the American Civil Liberties Union, each couple has sixty days to solemnize their marriage through an officiant. The top of each provided marriage license cites state law, IC 31-11-4-10: "A license to marry shall become null and void unless a marriage is solemnized thereunder within sixty days after its issuance."
Keep in mind that the Indiana Attorney General's office has issued guidance to county clerks informing them that the processing of all marriage licenses for same-sex couples should be on hold until further notice. There is no provision provided by either the court or by the state government as to the validity of marriages performed during that window. That matter is likely to be decided in court.
If a same-sex couple is denied the free legal name changes afforded by their recorded marriage at their local Social Security Office, the couple should file a gender discrimination complaint with the regional SSA office in Chicago. That contact person is Cynthia Fulton: 312-575-4050