Here are the 2015 major rule changes as summarized by Rogers Redding, the National Coordinator of College Football Officiating:
Crew of Eight Officials: For about thirty years the rules have allowed as many as seven officials on the field. Based on an approved experiment by the Big 12 Conference, the rules now allow for eight officials. The eighth official, the center judge (with the letter "C" on the uniform), is positioned in the offensive backfield opposite the referee.
I wanted to make a snarky joke about having more people to buy rounds at the bar after the game, but having one more official on the field makes a lot of sense given the increased size, speed, and scrutiny that comes with football these days.