It has been pointed out by several experts that our Holy Father pulled a neat dodge by making the Tridentine Rite an extraordinary form of the Roman Rite rather than a separate rite. Had he made it a separate rite, it would have been necessary for priests of the Latin Church to be given special permission to celebrate it; just as they need special permission to celebrate, say, the Syro Malankara Rite. By making it clear that there are two forms of the Roman Rite, he cut through all the red tape which would have impeded clergy from using it.
But there is a third form of the Roman Rite: the Anglican use of the Roman Rite, used in the US by former Anglican parishes. This was set up with massive encouragement by ... no less a figure than Joseph Cardinal Ratzinger. It uses The Book of Divine Worship, which is in effect the Anglican Book of Common Prayer with Dr Cranmer's heterodox Eucharistic prayers replaced by, for example, a 'Tudor English' translation of the Roman Canon familiar from its use in Anglo-Catholic Altar missals of the pre-Concilar period (incidentally, it is not Coverdale's translation).
This form of the Roman Rite, of course, overlaps intriguingly with the Tridentine Rite. Most of its Mass Popers, being taken from the medieval English Sarum Rite, have the same Collects, Epistles, and Gospels as the Tridentine Rite - although in the period post Trinitatem there is some dislocation, inherited from Sarum. Earlier generations of Catholic Anglicans supplemented the Prayer Book by adding Introits, Secrets, etc., from the Roman Missal and the'English Missal, still in print, represents the final flowering of this tradition and offers a splendid means of saying the Tridentine Masss in superb English.
So, if my Devon friend Fr Peter Morgan, ordained in the SSPX and latterly offering a dual ministry, one to an Anglican Papalist congregation and the other to a Tridentinist group, invited me to preach at the latter celebration, a sermon written for my BCP congregation at Broadwood Widger 20 miles to the north, would fit. In this blog, I can kill two birds with one stone by commenting on the Tridentine propers: bird 1 being adherents of SSPX or FSSP; bird 2 being the Prayer Book Society. I used to explain to the probably bemused folks of Broadwood Widger that their closest allies were SSPX, and that Benedict XVI was the first pope ever to be a Prayer Book enthusiast.
I very much hope that both of the minority forms of of the Roman Rite will have a great future. As far as the Book of Divine Worship is concerned, it has one problem in its present form. It assumes as its base an American version of the Prayer Book. For the Anglican Use of the Roman Rite to spread, I would suggest the following methodology: a decree providing (1) that certain specified versions of the Prayer Book (and Common Worship and English Missal) authorised in particular Anglican provinces were hereby authorised but (2) with their Euchristic prayers replaced by the formulae herein provided and (3) with certain supplementary provisions (e.g. for December 8; August 15, etc. etc.).
Such a provision would not only be useful for Anglican groups entering into full communion with the Holy See, but would undoubtedly influence the worship of those whose unity with Rome was still impaired.