Pinkie was really well-written in the most recent episode. I'm not usually a fan (she's the only main cast member I don't like) but she claimed most of the episode's great moments. Pinkie is really at her best when the writers acknowledge what a pain in the arse she can be.
Also, I dunno why people are getting on poor AJ's case about being "dishonest". Firstly, she never lied. Secondly, just because a pony embodies a particular element, it doesn't mean she will always act accordingly. Everyone has their bad days. We have seen Rarity being selfish, Pinkie being depressed and so on... often in far more blatant fashion than AJ's technical concealment of the truth in this episode.