By way of Rorate Caeli, in turn by means of Le Forum Catholique, Bertone confirms motu proprio.
The excerpt comes from the French journal, Le Figaro and apparently includes the following:
Is a Decree widening the possibility of celebrating the Latin Mass according to the rite from before Vatican II (the so-called Mass of Saint Pius V) still expected?
[Secretary of State] Cardinal Bertone: The merit of the conciliar liturgical reform is intact. But both [for reasons of] not losing the great liturgical heritage left by Saint Pius V and for granting the wish of those faithful who desire to attend Masses according to this rite, within the framework of the Missal published in 1962 by Pope John XXIII, with its own calendar, there is no valid reason not to grant to every priest in the world* the right to celebrate according to this form. The authorization of the Supreme Pontiff would evidently preserve the validity of the rite of Paul VI. The publication of the motu proprio which specifies this authorisation will take place, but it will be the pope himself who will explain his motivations and the framework of his decision. The Sovereign Pontiff will personally explain his vision for the use of the ancient Missal to the Christian people, and particularly to the Bishops.
Of course, the "when" of the question still remains.