That being said, it is true that the booklets are really rather well put together. I would buy one. They have everything one might require for assisting at the Papal Liturgies, and a good deal more.
What I immediately went to have a look at was the setting for the Mass throughout, by James MacMillan. It's only a melody line, so one has to imagine the harmonies, but for the most part this isn't difficult.
(Later note: You can see a link in the comments box, from Mac [thanks!], to a synthesized sound version)
I wrote a post about a week or so ago which I never put up on the blog for various reasons. Damian Thompson had been having a go at some music written by a friend of mine, which actually I thought was quite good. In the course of his piece, Damian extolled again the music of James MacMillan, and compared it (in general) to this other piece. It got my mind working. The bit that I wrote was to make the point that actually it is rather hard to write a Mass setting for unison congregational singing that doesn't resemble, by and large, all the others: MacMillan has a setting already in the general repertoire called, if my memory serves me right, the St Anne Mass, and it's a nice piece in a rather Scottish manner, but not head and shoulders above, say, the Dom Gregory Murray Mass or any number of others. His new Mass for the Papal Visit even uses what is for me the kiss of death, cantors singing lines for the congregations to sing back to them. (Again, see Mac's comments)
I think that the problem lies with a too-close approximation of these Masses to hymn tunes; I mean the feeling that one has to set the sacred texts to a four-square melody, more or less one syllable to one note, with the occasional melisma or modulation for interest. However, because most of the Mass texts are not metrical, but plain prose, the longer pieces, such as the Gloria do not sit easily with this style of music. To put it plainly, I don't think you can set the Gloria in 4/4 (or any other beat) at all without it sounding dull, and the same goes to a lesser extent for the other movements of the Mass. The Gloria especially is too long for a memorable melody; tunes simply wander around going nowhere in particular. You can spice it up in other ways (different movements, different forces, different keys) but if you're not careful it can end up sounding either like a Broadway musical or simply dull.
There are good congregational Eucharistic settings in English, but the best two I can think of are Merbecke's setting of the Communion Service and Shaw's Folk Mass (not at all what that title conjures up these days), both Anglican pieces. These two eschew time signatures, employing free rhythm and modal tonality—in short they have more in common with plainchant than with a hymn tune. Neither uses melismas, though, these being forbidden by Cranmer; this is a pity as they might have given further interest. Both settings work very well congregationally, and manage never to be dull.
In a Catholic context, I think of the astounding Missa Cum Jubilo of Maurice Duruflé. This is a unison setting for seminarians, and draws very heavily on Mass 9. It also requires a strong lead from an able choir, and an above-averagely skilled organist. But it is probably doable in a larger church, and has the advantage of being an important work in the classical repertoire in its own right.
The same (in a completely different way) can be said of Schubert's Deutsche Messe. However, in practice, as things stand, only the Sanctus of this Mass can realistically be used, because all the movements have been versified and paraphrased within an inch of their lives, and this practice, thankfully, is to be discouraged in future, I understand.
Paul Inwood has produced a Mass based loosely on the opening phrase of the Kyrie from Mass 11. I am familiar with the Sanctus from this Mass, and can say that it stands head and shoulders above anything of his that I have heard before. I am not so keen on one or two of the other movements, which would seem to return to a former style, but if this signals a greater interest in the 'feel' of plainchant, then it is good news. His Sanctus does have a time signature, but has enough atmosphere and, actually, brevity, to make it work; the music does not dominate the text but gracefully illustrates it. This setting has been commissioned by the Diocese of Arundel and Brighton for its forthcoming jubilee in 2015 (the diocese having failed to interest James MacMillan in the project). If Paul Inwood can be encouraged in the direction he has started out in for his Sanctus through the remaining movements, this Mass could be a serious contribution to a newer and better register for congregational settings, and this is something we need seriously to develop very soon, before we bed down again into the old tired style of which, I fear, our Papal Visit Mass may be simply one more example.