The slow revolution initiated by Summorum Pontificum continues. Catholic seminaries will be instructed from Rome to train priests in both the Novus Ordo (the missal of 1970) and the Extraordinary Rite (the missal of 1962).
It is a logical development -- Rome has said there is one rite, and two forms. It stands to reason that a priest will have, as part of his formation, the knowledge of how to offer both forms of mass.
Naturally, this will dislodge a few other stones in the slowly building avalanche -- seminaries have a finite amount of time to prepare priests, so this is also a way in which Rome wrests control of the course offerings of the seminaries. The Extraordinary rite requires a better grasp of Latin than the average parish priest has, so more time will have to be spent on Latin. The underlying theology of the Mass will also have to be explained at greater length. The rubrics of the Mass will have to be practiced. Gregorian chant will have to be revived for sung masses.
Central to Benedict's theology -- and to the Catholic church -- is the Eucharist. The Eucharist is the heart of Catholicism in the same way that Scripture is the heart of Protestantism; the Tridentine mass exalts the Eucharist in a special and sacred way. Benedict understands that if you emphasize the holy, spiritual nature of the Mass, you in turn improve the priesthood -- which is in need of both qualitative and quantitative improvement. Much of the focus of the press has been on the numerical problem of Catholic priests; Benedict understands that there is also a qualitative problem. He also realizes that if there are fewer priests, they must be formed better -- and better-formed priests will increase vocations in the next generation.
To use an analogy from football, Benedict is getting back to fundamentals. The Tridentine mass is a return to fundamentals -- it is rubrics, blocking, and tackling. Latin and chant are skills that have eroded in the last forty years; to be saved for future generations, they must be emphasized now. A greater emphasis on Latin also puts priesthood in touch with its intellectual patrimony -- the theology of the fathers and of Scholasticism become more accessible. Benedict is returning the priesthood to the mass, and saying to them, "This is what we do. Do it properly, and the people will come. Do it properly, and the next generation will seek to learn it."
Run the football, and you gain control of the game. Fix the mass, and you gain control of the Church. Fix the Church, and the whole of society improves.