Chrisitna Perri's tweet:

We're excited to announce that "A Thousand Years" -- featured on The Twilight Saga: Breaking Dawn - Part 1 Original Motion Picture Soundtrack -- will be available beginning Tuesday, October 18th! The album arrives in stores and online on Tuesday, November 8. 

 

A 30-second preview will be available on The Twilight Saga Facebook page starting this Thursday, October 12 (on the special "Soundtrack" tab) + a brand new lyric video by the amazing Elliott Sellers will premiere exclusively here on ChristinaPerri.com beginning at midnight October 18!

Sources Christina Perri twitter her blog and via  F*** Yeah twilight Saga Music.