Don't have time to go into too much detail...no time, heh. But still wanna geek out. Spoilers ahead! In no particular order, just as they come to mind...
Las Pegasus? I loved that name.
Okay, who else's mind went to a very bad place when RD and Spike decide to mess with Twilight when she was trying to remain perfectly still. No? Just me? I mean, my mind didn't go there....no...
I always wondered if the guards in the castle knew who Twilight was, ever since the guards looking for Philomena didn't know who she was. Now I know...the library guards know. And What about the Princess?!?! Just randomly walks by? LOL. Trollestia.
Pinkie as a fortune teller? I really have to finish that story before canon destroys everything about it...
Cerberus and the gates of Tar-Tarus? I assume that's how it's spelled since she pronounced it so weird. And Fluttershy taming the three headed dog was too cute.
Rarity only seemed to help out by making sure everypony else looked good....well...good to know in a crisis.
Can't think of anything else at the moment. LOVED the episode. I kinda miss having Twi in every episode. And so much canon for writers like me to work with ^_^ At least I felt like it. Anyways, gotta go, BYE!