Spoiler

I don't think it's been confirmed yet. I read in some interview that there's a possibility she may be back at some point. Though, I doubt they're writing/talking about the next season yet, so we probably won't hear anything for awhile.

I would love her to come back, but I honestly think that would be too much for her. She left because this isn't her place anymore. She doesn't need to fed that dark alter-ego inside of her like Dexter does.