Apparently, the Pope has a new book out that according to a CNN story "debunks several myths about how the nativity unfolded." That he is admitting to some of the various false notions surrounding the Jesus narratives is not that impressive when you consider that every point mentioned in the piece has long been recognized as mythical/folkloric elements real scholars. The overwhelming majority of scriptural scholars, many of them believers, reached consensus on a number of these myths decades ago. Most of the details that have been "debunked" don't really matter. The overall purpose of Christmas is to celebrate the birth of Jesus regardless of the day and/or year he is supposed to have been born. Going by scripture it is almost certain that Jesus was not born in the month of December (by adjusting to modern calendars). It has also long been acknowledged that the discrepancies in the Bible make it impossible to claim any specific year for Jesus' birth. It is estimated to fall within a 10-12 year time-frame, depending on which version, translation, and interpretations are used.
As far as I can tell all Ratzinger has done is repackage settled scholarship. I won't be looking to get a copy of this book.