Words such as "wow," "whoa!" and "stunning," have peppered my Facebook feed all morning. But Pope Benedict's announcement that he is stepping down should not come as too much of a surprise. He said himself on a on a number of occasions that the pope has the right and perhaps even the obligation to resign should he feel unable to carry out the duties of his office.

In light of his increasing frailty, the decision also reflects Benedict's personality. For decades the world watched the long, slow decline of Pope John Paul II, who characteristically shared his suffering in a very public and poignant way. His successor, a scholar who has never been very comfortable in the limelight, has chosen to impart to the faithful a different lesson: how and when to make a courageous exit.

Benedict's announcement has prompted widespread debate over his legacy. Any assessment of this will require acknowledgement of his distinctive achievements as pope, including his three encyclicals and other writings and speeches in which he used his formidable intellect to integrate faith and reason in the modern world. But any present or future evaluation must also recognize that Benedict's papacy has also been marked by moments and actions far less grace-filled than the announcement of his departure. Among these are the clergy sex abuse scandals, dissension and dysfunction in the curia, and repeated papal gaffes -- at Regensburg in 2006 about Islam, about indigenous people in Brazil in 2007, and on the subject of condoms in Africa in 2009.

And, of course, any assessment of Benedict's legacy depends on who is doing the assessing. More traditional Catholics have welcomed Benedict's vision of a robust Catholic church armed against the evils of a secular world. But that vision has alienated many progressive Catholics in the United States, especially given his suggestion that the church would be better off without dissenters. Many suspect that mentality was behind the Vatican's announcement, last April, that the Leadership Conference of Women Religious would be placed into a receivership until their orthodoxy could be certified.

And this morning, Benedict opened his announcement with the salutation "Brothers," but one wonders what the news signifies for Catholic sisters, American and otherwise. In their official statement today, the Leadership Conference of Women Religious tactfully thanked him for his service and wished him well in his retirement. But the question surely at the forefront of their minds, and those of many Catholics, is what his resignation will mean for the Church of the immediate and distant future.

Much depends on who will be elected to succeed Benedict. The speculation began at once. As was the case in 2005, many predict that the next conclave will result in a non-European pope. The composition of the College of Cardinals would suggest that such an outcome is unlikely though not impossible. Either way, considering that all the papal electors were appointed by Benedict or his predecessor, it is certain that his legacy will extend far beyond the time he spends as pontiff emeritus.