I thought Regina’s line about regret fit perfectly into her redemption arc and was not backpedaling at all. I agree completely that true redemption will require her to express remorse, but she’s not there yet. Her statement was an insight into where her progress toward redemption is at the moment.
I love the story of Regina’s redemption precisely because it has been a gradual development and not a sudden, 180 degree reversal. We’ve seen her go from full, Evil Queen mode just before she cast the curse, to showing compassion mixed with cruelty by letting Owen go just before she killed his father, to tonight choosing to keep Henry despite the risk he posed to the curse, to trying to help Emma save Henry at the end of the first season even though Gold told her that sacrificing Henry would be the price to keep the curse unbroken, to expressing remorse for what she had done to one person (Henry) in “We Are Both”, to trying to improve her behavior in order to win Henry’s approval in the first half of season two, to being willing to sacrifice her life for everyone else in the second season finale (although that was probably more out of concern that Henry not be left alone than concern for everyone else.)
The point is, all of these things are steps in her redemption. The difference between regret and remorse is significant, but even if we say she has no remorse (instead of no regret), I still don’t think she is backsliding like she did when Cora came to Storybrooke. I just think remorse is a stage she hasn’t yet reached. She is making great progress but that doesn’t mean she is there yet. It’s the slow but steady progress that makes the character fascinating. It would be unrealistic if she suddenly jumped from being so evil to being good. Likewise, it would be annoyingly bad writing if she constantly oscillated back and forth from good to evil, but a steady, two steps forward and occasional one step back progress from evil to good is much more interesting and it mirrors her earlier transition from good to evil. At least, that’s how I see it.