Starting on November 27, 2011, all Roman Catholic churches in the United States began using a new English translation of the Roman Missal (the 3rd edition). The Roman Missal is the ritual book that contains all the prayers for the Holy Mass.
These new English texts are the culmination of a process that has lasted many years. The former English edition of the Mass came from a hasty initial translation of the "new Mass" in the 1970s, which employed a translation principle that allowed for paraphrasing the official Latin texts.
Blessed John Paul II sought to ensure that all vernacular translations of liturgical texts throughout the world would more closely correspond to the original Latin. He noticed that, especially in the English version, entire phrases of the original prayers were being too often lost in translation.
The International Commission on English in the Liturgy (ICEL) was charged with preparing the new English translation that would serve the U.S., Canada, England, Wales, Ireland, Scotland, South Africa, Pakistan, India, Australia, New Zealand, and the Philippines, in addition to other smaller communities throughout the world. This process took the ICEL nearly ten years to complete.
The words we pray at Mass are slightly different, but the Mass itself has not changed. Although replacing a set of prayers we have used for 40 years will not be easy, it nonetheless presents a great opportunity for the English-speaking Church. The new translation will make possible an increased sense of beauty and reverence in the sacred liturgy, which will hopefully contribute to our common vocation to holiness.
Excerpts from: The New Translation of the Roman Missal: Why A New Translation, a bulletin insert series provided by the Office of Worship in the Diocese of Fort Wayne-South Bend