First of all, I absolutely love that title. Second, I think that would work out much better for the finale, as an episode with right amounts of drama and comedy. That would be nice.
Well, as I said, even if she does become a princes that doesn't mean she's going to become an Alicorn nor leave Ponyville. Besides, it's been all but confirmed that there will be a season 4.
It's funny how terrified people are of something really upsetting the show's status quo. It won't happen, of course, but I wouldn't mind something radically shaking up the show's formula.