The Walt Disney World resort has made the following announcement:

Quote Originally Posted by The Walt Disney World Resort

Take flight and feel the wind through your hair as you fly above breathtaking vistas of California.

Soarin' will close for refurbishment beginning January 4, 2016 and shall reopen in the summer of 2016.
In addition to the third theater currently under construction, Epcot's Soarin' attraction is expected to receive renovations to the queue area and the same projector upgrade that its Disney California Adventure counter-part recently received.

It has not yet been confirmed if the third theater and new "Around the World" film will open in Summer 2016 or debut later in the year.