I think the above title reflects well recent movements from Benedict XVI who has been spending his theological captial "correcting" the "mistakes" of Vatican II. According to this press release, he apparently has claimed that "Orthodox churches are defective and other Christian churches are not true churches." Boy, shocking--on the order of dog bites man. As Benedict goes on to explain in the article, "Christ 'established here on earth' only one church," the document said. The other communities "cannot be called 'churches' in the proper sense" because they do not have apostolic succession — the ability to trace their bishops back to Christ's original apostles.
And this remains one of the fundamental challenges that the Roman Catholic Church still presents to Protestantism--how is it possible to affirm "one holy catholic and apostolic church" when Protestantism is broken into hundreds of denominations? For Roman Catholics, the only way to preserve unity is to point to apostolic succession, a line of ordination that goes back to the apostles. For Protestants, the means for unity is also apostolic succession, but it is a succession of commitment to the apostolic message and mission (Ephesians 2:11-22; Matthew 28:16-20). As the authority of Word and Spirit continues to be observed in Protestant churches, we manifest the unity of Christ's church even in the midst of our denominational groupings.