I think Regina will be tempted to revert – afterall, who wouldn’t want to hurl some fireballs at the heads of people you’re PO’d at?! 🙂 – But I think, ultimately, she’s experienced both light and dark, and after true love’s kiss with Henry, I think she’ll realize reverting is only going to make her feel good for a moment, and she’ll still have to deal with the pain in the end. And I think Snow will help her with that — I think Regina and Snow have grown close enough that though Regina might push back at first, but will ultimately let Snow in to help.
Although I hope they let Regina teeter on the edge between good and bad a bit! Regina on the edge is fantastic to watch!!