According to Italian news agency Adnkronos, the Pontifical Commission "Ecclesia Dei" will soon publish an order addressed to seminaries "in which it is required that the celebration of the Latin Mass be taught to future priests":
"According to what has been learned from authoritative sources, the dicastery presided by Cardinal Darío Castrillón Hoyos (among the main supporters of the return of the Mass according to the pre-Conciliar rite) would be considering a circular addressed to seminarians which, in practice, is aimed directly to those bishops who [are] 'disobbeying' the Pope's motu proprio (...)."It is not entirely clear from the report if the order will be an exclusive document or if it will be part of the general document of clarification of the motu proprio Summorum Pontificum which will be published shortly (according to several news agencies and sources).
UPDATE (Sunday, 2300 GMT): The news of this order which would be sent to seminaries was confirmed this Sunday by the Vaticanist of Italian daily La Stampa, Marco Tosatti. It remains unclear if this norm would be a specific document or if it would be part of the clarification document.
Tip: Le Forum Catholique.