The plaintiff-appellants in Seven-Sky v. Holder (the case formerly known as Mead v. Holder) have filed their opening brief at the D.C. Circuit. Again, this is a case in which District Court Judge Gladys Kessler upheld the minimum coverage provision as a permissible exercise of Congress's authority to regulate interstate commerce (though she held that it was not a valid exercise of the taxing power). An exact date for oral argument has not yet been set, but the scheduling order indicates that it will take place some time in September.
You can access the brief here.