I was surprised by the news of Pope Benedict’s resignation, because papal resignations have so rarely happened. When it happened the last time, unless I’m mistaken, it served as mechanism for settling a long-running, embarrassing schism. There’s nothing like that happening in this case, of course, so it’s even more unusual while being less significant in its implications. So I can understand why the announcement would come as such a shock, especially to those that identify strongly with Pope Benedict and what he represents, but it seems to me that this is a good decision for both the outgoing Pope and for his church.
If Benedict believes that he is no longer able to serve effectively, I don’t see how he could have remained in good conscience. He wouldn’t be doing anyone any favors to try to continue serving when he no longer believed himself able to do so, and it wouldn’t do him or his church much good to hang on for as long as possible. Benedict was first and foremost a theologian and scholar, which is one reason why he is so well-liked by many orthodox (and Orthodox) Christians, but I suspect that his temperament and training remained those of a scholar rather than a pontiff. When he was elected, I recall that many people assumed that he would be acting mainly as a steward for a short time because of his advanced age, and so he has.