the 2009 document Anglicanorum coetibus, in which the Pope responded to the requests of disaffected Anglicans who want to enter into full communion with the Catholic Church in a way which preserves the good and unique aspects of their Anglican heritage - aspects such as beautiful hymnody and choral music and unique prayer and liturgical traditions. As described in the establishing document, the purpose of the ordinariate is "to maintain the liturgical, spiritual and pastoral traditions of the Anglican Communion within the Catholic Church, as a precious gift nourishing the faith of the members of the Ordinariate and as a treasure to be shared."
On the technical side of things, a personal ordinariate is a Church structure similar to a diocese, but one that is nation-wide and led by an "ordinary" (a priest or a bishop) who is answerable directly to the Pope. Much like a diocese, an ordinariate has parish churches, priests and faithful. Naturally, the parishes that will be part of the Anglican ordinariate will preserve Anglican forms of worship and governance while being fully "Catholic" in their faith and in their relationship to the Successor of Peter (i.e. the Pope).
The first Anglican ordinariate, named Our Lady of Walsingham, was established last January in England and Wales. Yesterday, it was announced that the U.S. version is called the Personal Ordinariate of the Chair of St. Peter and it will be headquartered in Houston, Texas at Our Lady of Walsingham Church. Fr. Jeffrey Steenson, formerly the Episcopal Bishop of the Rio Grande but now a Catholic priest, will be the ordinary for the structure in the U.S.
For the vast majority of American Catholics, this development will not mean a whole lot. As you travel to different cities in the future and look for a place to fulfill your Sunday obligation to attend Mass, however, you might now have a few more choices. But from a Southern perspective, the birth of the ordinariate is interesting because many of the long-established Anglican parishes and groups who are lined up to join the Church through the ordinariate are in Southern states - especially Florida and Texas (the latter of which is the birthplace of Anglican Use Catholic parishes). You can take a look at the unofficial Google map of these communities.
Pray for these brothers and sisters of our who are beginning their journey into the Catholic fold and pray for our Holy Father, Pope Benedict, who is the Pope of Christian unity!