Okay, so this seasons we're going to have the "Princess Coronation." God freaking dang it. Alicorn Twilight is almost certainly a definitive fact, and apparently she's going to become a princess as well. Oh my gosh what is that? A shark? Whelp it looks like we better jump it!
We've also got a synopsis for the finale. Season 3 Episode 13 - Magical Mystery Cure - When Twilight casts a spell that switches the Cutie Marks and destinies, the only way to reverse the spell is by writing her own magic.
Now I don't know if this is going to have the coronation in it or if the coronation happens in episode 12 or something Either way, we're just going to have to wait and see.