Pope Benedict's midday Angelus reflection and his words at the statue of the Immaculate at the Piazza di Spagna yesterday, for the Solemnity of the Immaculate Conception, are available online in a couple of places.
English translations of his words at the Angelus prayer have been posted by Zenit and Papa Ratzinger Forum. English translations of his words at the Piazza Spagna are also available at Zenit and Papa Ratzinger Forum. There are news articles about both events at Asia News (Angelus and Piazza Spagna), Catholic News Agency (Angelus), Zenit (Angelus and Piazza Spagna), and Catholic News Service (Piazza Spagna with reference to the Angelus).
At the midday Angelus, he spoke of the mystery of the Immaculate Conception, which he said reminds us of two truths: "in the first place original sin, and then the victory of Christ's grace over it, a victory that shines sublimely in Mary Most Holy." He also said:
In the afternoon, the Holy Father brought a basket of white roses to the statue of the Immaculate (photo at Papa Ratzinger Forum), and he spoke of roses and of their thorns. He explained the traditional roses, saying "It has become tradition that the Pope joins in the homage of the city by bringing Mary a basket of roses. These flowers indicate our love and our devotion: the love and devotion of the Pope, of the Church of Rome, and of the inhabitants of this city, who feel themselves spiritual children of Mary."