My thoughts on the 3 spoilers from Comic con · 10:11am Jul 15th, 2012
PREDICTION TIME!!!!
1st line... "Princess Cadence needs our help, her magic will not last forever."
Her main spell is the love spell, which was used to end an argument in pt1 of the wedding episode. With that fact, plus the music line, it can be perceived that Cadence is in the Crystal Kingdom, using her magic to prevent fighting.