I'd say there's gonna be a fan-backlash no matter what happened x3
I mean, I think everybody already knew that Discord was going to be reformed. Then what was everybody expecting? That they'd leave Discord free reign as a villain or that they turned him back to stone saying 'we tried'? x3
Personally, I think this was a great episode. I mean, we got lots of Discord and lots of Fluttershy, who really has come a long way since the first episode. She's learned a lot from her experiences with Iron Will and was able to stand up to Discord here, people!
Besides, having Discord say 'Friendship is Magic' was just priceless XD