I can recommend reading Mgr Andrew Wadsworth's talk given to the clergy of Westminster entitled "Sacrosanctum Concillium - What we have done and what we have failed to do." It's given in full over at the Chant Cafe. Mgr Wadsworth is always clear, straight forward and refreshing on the liturgy, although you need to appreciate the questioning look and dry sense of humour in his delivery to get the full effect of some seemingly easily overlooked phrases that in fact convey a world of meaning. He makes it clear that these are personal perspectives, and while I may not agree with all his assessments, he's in a pretty good place from which to make some judgements. He recognizes some good achieved, he points out that there is still much to do. Sacrosanctum Concilium is as much honoured in the breach of its injunctions than in their observance. My own comments in red.
On the challenge of the liturgy conveying the divine to the human and lifting the human to the divine:
The overwhelming character of many Masses is still hopelessly horizontal and assembly-oriented. The considerable challenge which all of this presents is not to be underestimated and requires the offering of the very best that we have in each of these important areas. Too often, the liturgy can seem to be hopelessly earth-bound and pedestrian rather than stimulating in us a thirst for God and all that he longs to give us and do in us and through us.
False ecumenism has had a catastrophic effect in this sense – many Catholics now tend to see themselves (both individually and collectively) as just one subjective response to the human dilemma, whereas Sacrosanctum Concilium is telling us quite emphatically that the Church is God's most effective response to the highly human dilemma.
On actual participation:
The Constitution underlines, however, that for the liturgy to achieve its fullest effect, the faithful must take part with knowledge, actively and so fruitfully. I think it is fair to say that the requirement of knowledge implies a catechesis that in many ways is yet to be undertaken. [I would suggest that although people now take part more actively in a physical sense, they actually understand rather less about what is supposed to be going on in the liturgy.] It also highlights the fact that the rightful full, conscious and active participation of the Christian people in the liturgy can only be achieved by adequate instruction, above all, of the clergy. This, we would also want to admit is a work in progress and some of the strangest notions concerning the liturgy are the province not of the laity but the clergy.
Clearly the question of language loomed largely at the Council and it seems that the adoption of the vernacular was considered inevitable and desirable but it seems equally clear that the total exclusion of Latin was neither desired nor envisaged. Certainly there is nothing to account for the visceral hatred of Latin that has characterized the liturgical approach of some who claim their authority from mandate of the Council.
Whilst Latin has made something of a modest return evidenced by Latin chants which now can be heard more frequently at Mass, the truth is that most parishes have had fifty years of the studious avoidance of anything Latin, lest there be a sense of the continuation of anything that was formerly found in the liturgy. The hermeneutic of rupture is most dramatic in this exclusion of Latin. Not only do we now have several generations of Catholics who cannot sing Credo III or the Salve Regina, more seriously, we have several generations of priests whose Latin is insufficient to cope with any element of Latin in the liturgy, let alone the celebration of the Mass in Latin in either form of the Roman Rite.
The place and importance of Latin is not determined by the choice of liturgical language. It is vitally important that we grasp this. [Almost our entire history is in Latin, thus the hermeneutic of rupture has had such a severe effect on every aspect of the Church.] Even in the case of an entirely vernacular liturgy, we still need Latin to be able to interpret so many of the sources of the liturgy, to say nothing of fundamental sources for both theology and philosophy. We shall have to recover a greater enthusiasm and competence in the teaching and learning of Latin if future generations of Catholics are going to be equipped with the necessary skills to explore the treasures of the Church’s ancient patrimony. In seminaries, the mandatory one year of Latin [if seminaries are now doing even this little, it's news to me.] provides little more than the briefest introduction to the language. In places where there is a greater requirement for the study of Latin, the students benefit across the board in their studies and the Church has a future generation of priests who will be more skilled in this respect. It is worth noting that Sacrosanctum Concilium envisages that every community of Catholics will know the basic chants in Latin.
On what we sing:
Many things which were indicated fifty years ago, such as the singing of the Mass, and more particularly the singing of the proper texts rather than the endless substitution of songs and hymns, are only now being seriously considered and implemented. [Not in many places that I know of.] It is earnestly to be desired that such developments continue to flourish and that an improved liturgical culture is accessible to everyone in the Church. Time will tell whether the musical resources necessary to the success of such a development flourish in our midst. If they do not, then I fear that many of the less desirable features of post-conciliar liturgical music may be here to stay.
As the good Mgr. says:
A new generation of Catholics eagerly awaits a greater experience of the basic truth that the liturgy is always a gift which we receive from the Church rather than make for ourselves. As those most intimately concerned with the liturgy, you all have a highly significant contribution to make to this leitourgia, this great work in which there are only participants and beneficiaries and no spectators. May God bless us all as we share in his work.