With the promulgation in 2004 of the decree "Redemptionis Sacramentum" the liturgical reform has reached a great turning point. The era of the Liturgical Movement which found its climax in the Second Vatican Council and the period following has acheived a real degree of maturity. Benedict XVI in his letter "Sacramentum Caritatis", an overarching liturgical teaching which corresponds with Pius XII's "Mediatror Dei", defines with some clarity what the Liturgy is now that so much has taken place because of the Liturgical Movement. Indeed, in the light of these two documents, we can say that the period of liturgical experimentation is over and that we are in a better position to undertake a genuine reform of the Liturgy - a reform of the reform you might say.
"Redemptionis Sacramentum" , unlike "Inestimabile Donum" (1981) which set out to correct litirgical abuses, is a clear statement of the true form of the Liturgy in the post-Conciliar Church. In "Sacramentum Caritatis" the Holy Father sets the current form of the Liturgy within the context of history, the Church and the Life of Grace. In doing so, he has enabled a more genuine development of the Liturgy to take place - that which was envisioned by the Council, but which became a period of experimental liturgy instead. Experimental liturgy is over. What we have is a Church which has experienced the experimental liturgy but which is clearer than it was about the nature of reform. The reform of the reform can now proceed with clear markers. Benedict XVI expresses this in one sentence of his letter:
What he is saying is that we need to return to what the Second Vatican Council actually said about the Liturgy and its reform, we have to appreciate what the Liturgy is in itself, we have to understand anew the unreformed Liturgy (Tridentine Liturgy), and we have to enable an organic development of liturgical form to occur (clearly, this is different from liturgical experimentation). We could expect that a reformed reformed rite, one that corresponds more with the intentions of the Second Vatican Council, including the question of the reform of the Tridentine Rite (which has never taken place), could arrive on our shelves within a couple of generations."Concretely, the changes which the Council called for need to be understood within the overall unity of the historical developmet of the rite itself, without the introduction of artificial discontinuites." (Sacramentum Caritatis, 3)