This is a disaster.

@Frustration in Excelsis  

 
Twilight was never good at being friends, “Princess of Friendship” was a stupid plot device. In fact she’s STILL incredibly awkward, blind, generalizing, and looks at people from the wrong angle - except the show now sides with her.
 
Now Pinkie, she may be obnixous but she’s also VERY sociable, she rarely ever tries to “fix” anyone but rather empathizes with the good qualities in eachpony that not many others can see. An older and more experienced Pinkie is - heck, I’m gonna say it - probably the most Celestia-like characterwe could have.  
Twilight on the other hand should drop this “teaching others friendship” business she’s terrible at and become her Luna ads the princess of Paperwork which Pinkie would be terrible at. (Pinkie would make a great symbolic monarch but a terrible governor.)

@Nightweaver20xx
 
I tend to agree. Pinkie’s highly caring and emphatic, and she’s naturally geared towards getting along and being friends with as many people as possible – in fact, I’d say she gives Twilight a solid run for her money for being the most friendship-oriented of the mane six – and going by her episodes with the yaks she doesn’t seem half bad at diplomacy either. Mostly, I think she would need to work on her patience… and the loss of her freedom to party with her friends at a drop of hat might be the most bitter part of princesshood for her to accept. Other than that… yes, I think she’d do a very good job of being an alicorn princess.

After many years, I actually have changed my opinion about Pinkiecorn. She’d probably make an excellent princess and wouldn’t cause the end of the world like many of us think. Though giving her the extra stamina and raw magical power of an alicorn may cause a few accidents of property damage if she got too excited.

Princess of Parties with twice the Cutie Mark