My first post on the story of Mother Teresa’s decades-long struggle with spiritual darkness struck some as “dismissive,” and for that I apologize. That particular reaction was against the press coverage – not the Time article, but the subsequent filtering that I just knew would be picked up as a shocking new revelation and used by two groups to promote their own agendas: professional atheists (per the Hitchens reaction in the Time piece itself) and fundamentalist Protestants, who would take her lack of “blessed assurance” emotions as a sure sign that Catholicism was, indeed, far from being Christian.  Michael Spencer at Internet Monk had to issue a warning to his commentors on his Mother Teresa post, for example, that he wouldn’t be posting comments declaring that Roman Catholics weren’t Christian.
So that was my point in the “not news” remark. Because the simple fact of the dark night isn’t – not in terms of Mother Teresa herself or in terms of Catholic understanding and experience of spirituality.  It is very good that this book and the coverage has made this more widely known to people who were previously unaware of either the specifics or the general, and it is one more gift of Mother Teresa to the world, a gift she gave out of her own tremendous suffering. What strikes me is once again, at its best, taken as a whole, how honest Catholicism is about life, and our life with God. There is all of this room within Catholicism for every human experience of God, with no attempt to gloss over it or try to force every individual’s experience into a single mold of emotion or reaction.
Some other recent reactions and responses that are very helpful:
James Kushiner at Touchstone
Anthony Esolen, also at Touchstone:

It is not a mysterious thing, after all, that a young and enthusiastic person should become disillusioned after a month or two of the squalor of the Black Hole of Calcutta.  People lose their faith all the time — and people gain their faith all the time, and often they are the same people.  What is mysterious is that after her visions of Jesus ceased, after all the inner consolations were taken away, after the locutions, what my evangelical brethren call “words of knowledge,” fell silent, still Mother Teresa clung to Christ.  She retained her faith without the emotional accompaniments (and here let married Christians take heed). She continued to serve the poor of Calcutta even though the nagging little viper at her shoulder must have whispered to her, constantly, “This is all absurd.”  Let us be absolutely clear about this: outside of the ambit of Christian culture, no one goes to Calcutta.  What Mother Teresa did, no one does, not even for a year, without having been influenced by the message and example of Christ.  And to live there for good, no one does at all without the virtue of faith.
     Towards the end of the excellent film The Inn of the Sixth Happiness, the rural mandarin (Robert Donat) announces his conversion to Christianity to his brethren of the village council.  He is moved not by theological argument but by the stunning example of courage shown, in utter selflessness, in willed poverty, in persevering charity, by the lady missionary (Ingrid Bergman).  He understands that when you see what is not only a new thing in the world, but a great goodness that the world on its own would never produce and cannot even explain, then you should submit to it and follow where it leads, with theology halting behind.  Here with Mother Teresa we have even more: a great goodness united to quiet suffering, unspeakable patience, and a kind of bright and steely charity, for how easy would it have been for Mother to try to salve her sores by “sharing” her feelings with her fellow sisters?  A worldly man may enter the Peace Corps because he “believes” in it and wishes to do good; he will not stay there one month after he has ceased to believe.  Mother Teresa never ceased to believe, even in and through the silence.
     Dubiety is inseparable from the human condition.  We must waver, because our knowledge comes to us piecemeal, sequentially, in time, mixed up with the static of sense impressions that lead us both toward and away from the truth we try to behold steadily.  The truths of faith are more certain than the truths arrived by rational deduction, says Aquinas, because the revealer of those truths speaks with ultimate authority, but they are less certain subjectively, from the point of view of the finite human being who receives them yet who does not, on earth, see them with the same clarity as one sees a tree or a stone or a brook.  It should give us Christians pause to consider that when Christ took upon himself our mortal flesh, he subjected himself to that same condition.  He did not doubt; His faith was steadfast; yet He did feel, at that most painful of moments upon the Cross, what it was like to be abandoned by God.  He was one with us even in that desert, a desert of suffering and love.  Nor did the Gospel writers — those same whom the world accuses on Monday of perpetrating the most ingenious literary and theological hoax in history, and on Tuesday of being dimwitted and ignorant fishermen, easily suggestible — refuse to tell us of that moment.
     In her love of Christ — and the world does not understand Christ, and is not too bright about love, either — Mother Teresa did not merely take up His cross and follow him.  She was nailed to that Cross with him.  She was one with Him — it was His greatest and most terrible gift — at the moment when he cried out to His Father, and the worldly Jews beneath mistook the name of God for Elijah.  We Christians must trust that she is also one with Him now too, sharing in the glory of His triumph over darkness and the grave.  “See,” He says, encouraging us to persevere and be fearless, “I have overcome the world.”

Carl Olson has an excellent post, as well.
In today’s Magnificat, a small meditation from Pope Benedict is included from a book called Dogma and Preaching, which is also pertinent:

The task set before the Baptist as he lay in prison was to become blessed by this unquestioning acceptance of God’s obscure will; to reach the point of asking no further for external, visible, unequivocal clarity, but, instead, of discovering God precisely in the darkness of this world and his own life, and thus becoming profoundly blessed.