Episode 14 of the Sword Art Online II anime ended with an announcement that the anime will begin the Calibur arc (pictured right) from Reki Kawahara's original light novel series on October 18 on Tokyo MX and other stations, followed by the Mother's Rosary (Mother's Rosario, pictured below) arc on November 8. These arcs will use a new opening theme song by Haruka Tomatsu, as well as a new ending theme song by LiSA.
The Calibur arc (light novel volume 8) revolves around the quest for the legendary sword Excalibur. In the Mother's Rosary arc (light novel volume 7), Asuna faces a duel against an secretive Avatar named Zekken for an Original Sword Skill.
A compilation episode, episode 14.5 "Debriefing," will air next Saturday with a preview of footage from the Calibur arc.
Thanks to Dennis R and Kagayaki for the embedded videos