(SPOILER)I would have loved to see an entire episode with the ponies with their incorrect cutie marks, and the other episode with Twilight fixing the problem and then having to go through the coronation of becoming an Alicorn/Princess.

I also came across something that interested me.

About the Four Princesses and what they represent.

Celestia - Day
Luna - Night
Cadence - ... Dawn (I guess)
Twilight Sparkle - Twilight (haha, because it's in her name)