Reports are that Princess Madeleine has not submitted any paperwork regarding a name change to the Swedish Tax Authority.
Previously, when I said that Chris O’Neill was ineligible to take Madeleine’s titles, that it was likely that Madeleine would become Princess Madeleine of Sweden, Mrs. O’Neill, and that she would not lose her royal style upon marriage because her marriage has been approved by the monarch. However, the article I’ve linked here suggests that taking Chris’ last name would require Madeleine to lose her status as Her Royal Highness.
Nothing concrete has been announced by the Royal Court, and even the Swedish Tax Agency cannot apparently decide one way or the other until after the wedding. (Then again, it took a friend of mine five years of marriage and a baby on the way before legally changing her last name, so it’s not like there isn’t time to decide these things.) We may not know Madeleine’s new style and title for sure until the Royal Court website updates their page on the Royal Family.