Pope Benedict XVI has certainly been "on a roll" lately with his pronouncements.
For one thing, he reminded everyone that it is the considered opinion of the Roman Catholic Church that many–if not most–non-Catholic Christian churches cannot be properly called a church. This kind of thing is not new; I dealt with this a long time ago in the piece We May Not Be a Church After All. Protestant churches just need to deal with this, both as they relate to the Roman Catholic Church and to prevent a repeat of its mistakes in their own organisations.
But a more visible change coming from the current Pontiff is encapsulated in his pronouncement Summorum Pontificum, which makes it easier for parishes to celebrate the traditional Latin Mass. Many non-Catholics are mystified by this move, so perhaps we can explore these issues in a more informed way than we see in some places.
First, some history: the ritual (or more properly the liturgy) of the Mass that the Pope is opening up is the so-called "Tridentine" Mass, which was formalised at the Council of Trent. From then until 1970 this Mass was the rite by which it was celebrated in the Roman Catholic Church. Until the Second Vatican Council it was necessary to celebrate this Mass in Latin; after that time it could be celebrated in the vernacular.
In 1970 the Tridentine Mass was replaced with the Novus Ordo Missae, the "new order" of the Mass. This Mass was made obligatory; it was not permitted to celebrate the Tridentine after that. (I recreate how that actually impacted Catholics and others in my book The Ten Weeks; a more technical treatment of the whole transition can be found here.) Since that time–and especially under John Paul II and Benedict XVI–there has been a loosening of the restrictions on celebrating the Tridentine Mass, and the current pronouncement is yet another step in this process.
But, you ask, why would anyone–other than Latin students–want to celebrate the Mass in Latin? It’s hard for anyone who has not been a part of Roman Catholicism to understand the appeal of this church to start with. But the whole Latin Mass business is tied up in a larger issue: whether our corporate worship is primarily for the purpose of affirming us as a Christian community or for directing worshipers toward God. The tug of war between the two has been going on for a long time, and the revival of the Latin Mass is yet another movement of the rope.
Although Pentecostals and Charismatics make a big deal of the times when the Israelites worshiped corporately (thus the endless repetition of 2 Chr 7:14,) the truth is that most of the worship surrounding the temple in Jerusalem was sacrificial in nature, thus very "vertical" in nature. (It was also largely liturgical in nature, contrary to popular opinion.) It was done to rectify man’s relationship with God. On the other hand, by the time Our Lord walked on the earth, between trips to the Temple Jews worshiped in synagogues, which had more of a "horizontal" component, i.e., an act of the community in addition to turning focus towards God.
The New Testament church carried over many habits from the synagogue, even with that "sacred pledge" (to use Bossuet’s expressive phrase) of the Eucharist, which was a community meal. (The results of that practice were uninspiring, which led to its abandonment.) However, as time passed, and the role of the Church assumed more parallels with Temple Judaism, the worship moved to a more "vertical" mode, a trend encouraged both by having the Eucharist as the normal setting for Christian worship and celebrating it in a language many worshipers didn’t understand.
One major result of the Reformation was an abrupt reversal of this trend. How abrupt the jolt was depends on the church; it ranged from a relatively mild change of course (Anglicanism) to a complete redefinition of the church (Anabaptism.) In Roman Catholicism itself, the "vertical" model of worship was enshrined for centuries, until the liturgical reforms of the 1960’s. Part of the rationale of these reforms was to put a more "horizontal" (community) emphasis on the Mass, which would complement a fuller role of the laity in the church. In addition to changing language and liturgy, the priest was now to stand behind the altar and face the people, rather than having his back to the altar and facing God. This one change does more to symbolise the intent of the reforms than even the language change.
The result of this has been that, for the last forty years, we have had a more "horizontal/community" emphasis in the celebration of the Mass. Unfortunately, in the hands of people who have more faith in faith than in God, the results of this can be pretty sappy. We are now seeing another reversal of trend with people who want their worship to be more God-directed. This can be seen in much of the "praise and worship" movement, although how successful this really is is a matter of debate. In Roman Catholicism, this manifests itself in part with a desire for the "Tridentine" Mass, and it is to these people that the current Pope is appealing to.
There are many things about the Roman Catholic Church that I find unacceptable, the concept of the Mass as a sacrifice being one and their view of the role of the church being another. But the idea that our worship of God be more directed towards him and not towards each other is appealing. If we would actually implement this on a meaningful basis, and direct our attention upward, then our life with those around us would be greater reflection of the ideal that Jesus Christ has set before us.