The Solemnity of the Annunciation of the Lord
is today. There is information on it here.
"Our sweet Christ, the Word Incarnate, has given Himself to us for every thing that was necessary for us, even to the hard and ignominious death upon the Cross. " - St. Philip Neri
Mary is the "Mater Creatoris," the Mother of the Creator
by Venerable John Henry Newman, C.O.
"This is a title which, of all others, we should have thought it impossible for any creature to possess. At first sight we might be tempted to say that it throws into confusion our primary ideas of the Creator and the creature, the Eternal and the temporal, the Self-subsisting and the dependent; and yet on further consideration we shall see that we cannot refuse the title to Mary without denying the Divine Incarnation-that is, the great and fundamental truth of revelation, that God became man.

And this was seen from the first age of the Church. Christians were accustomed from the first to call the Blessed Virgin 'The Mother of God,' because they saw that it was impossible to deny her that title without denying St. John's words, 'The Word' (that is, God the Son) 'was made flesh.'

And in no long time it was found necessary to proclaim this truth by the voice of an Ecumenical Council of the Church. For, in consequence of the dislike which men have of a mystery, the error sprang up that our Lord was not really God, but a man, differing from us in this merely-that God dwelt in Him, as God dwells in all good men, only in a higher measure; as the Holy Spirit dwelt in Angels and Prophets, as in a sort of Temple; or again, as our Lord now dwells in the Tabernacle in church. And then the bishops and faithful people found there was no other way of hindering this false, bad view being taught but by declaring distinctly, and making it a point of faith, that Mary was the Mother, not of man only, but of God. And since that time the title of Mary, as Mother of God, has become what is called a dogma, or article of faith, in the Church.

But this leads us to a larger view of the subject. Is this title as given to Mary more wonderful than the doctrine that God, without ceasing to be God, should become man? Is it more mysterious that Mary should be Mother of God, than that God should be man? Yet the latter, as I have said, is the elementary truth of revelation, witnessed by Prophets, Evangelists, and Apostles all through Scripture. And what can be more consoling and joyful than the wonderful promises which follow from this truth, that Mary is the Mother of God?-the great wonder, namely, that we become the brethren of our God; that, if we live well, and die in the grace of God, we shall all of us hereafter be taken up by our Incarnate God to that place where angels dwell; that our bodies shall be raised from the dust, and be taken to Heaven; that we shall be really united to God; that we shall be partakers of the Divine nature; that each of us, soul and body, shall be plunged into the abyss of glory which surrounds the Almighty; that we shall see Him, and share His blessedness, according to the text, 'Whosoever shall do the will of My Father that is in Heaven, the same is My brother, and sister, and mother.' "- Meditations and Devotions
There are posts on this feast all over the Catholic Blogosphere, including HMS Blog, Gerard Serafin, and Fiat Mihi. Mark Shea's post is especially notable, as it also remarks on this being a important anniversary in the Tolkien-verse: the day the One Ring was destroyed and Sauron defeated- a 'sub-created' echo of the True Eucatastrophe which began with a humble woman saying 'yes' to God.
"In Gondor the New Year will always now begin upon the twenty-fifth of March when Sauron fell, and when you were brought out of the fire to the King."
Gandalf to Samwise Gamgee, "The Field of Cormallen", The Lord of the Rings