Well I expected Discord to reform back to good (for the most part). I will see people complaining about their head-canon of Discord, but I don't really see him as truly evil, he just wanted to cause chaos and doesn't take consideration of how other people feel about his behavior.
The ending kinda felt rushed though. If it was longer, we could see more Fluttershy and Discord bonding, making Discord's realization more believable to me, but I really don't buy it.
A really good and fun episode though, minus the ending. It almost made this my favorite episode of Season 3 so far.