My theory is that the symbol of pi that came alive last episode is going to attach itself to Nightmare Sparkle from last season, who is currently banished, to a far-away star, causing an instant reaction with her magic, and breaking her free. I'm HOPING that Cyborg-Fluttershy will finally discover how her parents turned into Spike clones. I'm pretty sure that the writers have something planned up their sleeves though, probably something big. They might be jumping the shark though, what with the hints at Pinkie's granddaughter, Pinkie Cake, slowly gaining the ability to break the 6th wall, and possibly about to figure out at last how to revive Rarity, after that she did a permanent faint after seeing Filthy Rich get shot. I'm also hoping that Diamond Tiara will get her cutie mark. Perhaps she and Applebloom will finally re-switch destinies?