Updated: The Tablet article and comments are now here.
Updated again: I rather like Tigerish Waters observations here and here.
Q1: What is the significance of the language of "extraordinary form" and "ordinary form" in Summorum Pontificum?
A1: Explicitly, Summorum Pontificum speaks of "one Roman Rite" with two forms. From a juridical point of view, one should not consider one of the two forms as being in any way more "traditional" than the other form. [One might discuss in academic journals the historical development of the texts, but that is a completely different sort of question.] In a similar vein, a particular form of spirituality should not be seen as attaching to the celebration of one form rather than the other.
Q2: Should there be more celebrations of the extraordinary form in parishes as a result of implementing Summorum Pontificum?
A2: No, not necessarily. Summorum Pontificum makes it easier, from a juridical point of view, for celebrations of the extraordinary form to take place. This is intended, on the one hand, to help create a situation where groups who are not in a proper communion with the Holy See can be helped to regularise their situations, and, on the other hand, to ease the situation of those attached to the extraordinary form who take part in what one might call the ordinary life of parishes and dioceses. Nowhere in Summorum Pontificum, or in the accompanying letter to Bishops, is there envisaged the campaign to promote celebration of the extraordinary form that can be seen in some Catholic blogs, and associated with coverage of events such as the Latin Mass Society's training conferences.
Q3: Are there situations where celebrating Mass according to the extraordinary form should take precedence over celebrating according to the ordinary form?
A3: Two observations here. Pope Benedict XVI's letter to Bishops that accompanied Summorum Pontificum explicitly contains the expectation that the ordinary form of celebration will continue to be precisely that, the ordinary form. The letter bases this on the fact that appreciation of the extraordinary form arises from a particular liturgical formation that is not commonly found among ordinary Catholics, and on the "juridical norms". So my first observation is that the ordinary form remains the ordinary form, remains the ordinary form and remains the ordinary form. In the majority of pastoral circumstances, the presumption should therefore be in favour of celebrating in the ordinary form, and not allowing it to be in a certain sense "displaced" by the extraordinary form. As a second observation, Summorum Pontificum permits one celebration of the extraordinary form on Sundays and Holy Days, with, in my view, the intention that this permission should be used to respond to the situation of those attached to the extraordinary form; it should not, in my view, be used to promote the extraordinary form. In my view, the arrangement of such celebrations should take place in such a way that there is no appearance of the celebration of the extraordinary form "displacing" a celebration of the ordinary form - that would be to offend against the notion of the ordinary form remaining the ordinary form. One way to achieve this, but not the only way, might be for such celebrations to be seen as celebrations at deanery level, rather than individual parish level, with collaborative arrangements for celebration of the ordinary form in nearby parishes.
Q4: Does Summorum Pontificum have any implications for parishes where no celebrations of the extraordinary form take place?
A4: Yes, and one should not underestimate the importance of this for having a complete perspective on Blackfen's "little spot of bother". Pope Benedict's letter proposes an idea of "mutual enrichment" between the celebrations of the two forms, and this is clearly relevant to every celebration of the ordinary form wherever it takes place. The relevant passage from the letter follows, with my own emphasis added:
The celebration of the Mass according to the Missal of Paul VI will be able to demonstrate, more powerfully than has been the case hitherto, the sacrality which attracts many people to the former usage. The most sure guarantee that the Missal of Paul VI can unite parish communities and be loved by them consists in its being celebrated with great reverence in harmony with the liturgical directives. This will bring out the spiritual richness and the theological depth of this Missal.
The ordinary form can, in my view, contribute to the development of the extraordinary form in areas of participation by the congregation and a wider range of texts such as prefaces. But the extraordinary form can contribute to the celebration of the ordinary form a real sense of the sacredness of liturgical celebration and an attitude of faithfulness to the rubrics. This aspect of the phenomenon that is Summorum Pontificum has, frankly, been almost totally ignored in parishes and dioceses. And yet, it appears to me an essential part of the intentions of Summorum Pontificum with regard to its two directions of glance: both towards those outside proper communion with the Holy See (they will the more readily be reconciled if they can see the ordinary form being celebrated properly, in addition to their access to the extraordinary form for their own use) and towards those attached to the extraordinary form in normal parish and diocesan situations (there will be a real possibility of a kind of "mutual respect" between those attached to the two forms of celebration, that would avoid the occurence of "bother"). It is also the aspect of Summorum Pontificum that is relevant to most ordinary Catholics; it is in my view much more important pastorally than arranging for more celebrations of the extraordinary form.
Q5: Do I think Summorum Pontificum was a good thing?
A5: I have no attachment to the extraordinary form, so the juridical provisions of Summorum Pontificum with regard to the celebration of the extraordinary form do not directly affect me. I suspect that this is true of the vast majority of ordinary Catholics in the UK. I have no dissatisfaction with the Motu Proprio and accompanying letter in themselves. However, I am disappointed by the almost complete failure to implement the idea of "mutual enrichment", both in terms of the celebration of the ordinary form as discussed above and in terms of the development of the extraordinary form. Among the proponents of the extraordinary form, for example, I have tended to see a resistance to any development in the liturgical form (though I do recall an observation once about it being again a living liturgical form in the Church!). Another thing I am unhappy with is the feeling of being forced into "taking a stance" with regard to the extraordinary form, something that has happened, not because of Summorum Pontificum itself, but because of the promotion in favour of the extraordinary form that has taken place since. I am also disappointed in the continued use of the term "Traditional Latin Mass" (for example, in the title of a recently published CTS pamphlet) to refer to the extraordinary form, for reasons which should be apparent from my answer to Q1 above. It fails, in my view, to reflect the juridical status of the extraordinary form established by Summorum Pontificum.