Final Fantasy XIV will be expanding next month with Stormblood. As part of the lead up to the release, Square Enix has published a video featuring the main theme from Stormblood, Revolutions.
According to Yaevindusk's MMORPG.com forum thread, there are no real story spoilers, so it should be safe for viewing for fans looking forward to Stormblood in June.
Good find, Yaevindusk!