Cardinal Bertone has confirmed that
... there is no valid reason not to grant to priests in the entire 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.Catholic News Service, the news service of the US Conference of Catholic Bishops, has an article Tridentine Mass: Pope looks for bridge to tradition which admits that the MP is on its way.
(Text at the Rorate Caeli blog)
And Ignatius Insight has an article The Latin Mass: Old Rites and New Rites in Today's World
It's not looking good for Peter Griffiths who wrote in the Catholic Times who spoke disparagingly of the coverage of the forthcoing Motu Proprio saying "Well, much of that now seems to have been spin – spun magnificently by the ultra-conservatives and traditionalists". He seemed to think that Sacramentum Caritatis was an alternative to the Motu Proprio.
Fr Z has the text of the article and commentary at Ultra-conservative Tridentine Rite spin doctors
The latest guesses seem to be Maundy Thursday. Now that would be fun - the semi-non-penitential character of the day would seem to allow for Fr Z's suggestion of popping open a bottle of Veuve Cliquot and it would be the eve of the anniversary of this blog. I'll take the MDA to the Chrism Mass, I think :-)