Speaking of the diversity of liturgical rites and uses, particularly as pertains to the Latin West, some of you may be interested in this series of videos you can look at online:
Solemn High Ambrosian Rite Mass
Apparently they are trying to collect enough people to make it worth their while to make copies of this to DVD and VHS.
The recording was done in Rome, and appears to be part of the celebrations that occurred during the 10th Anniversary of Ecclesia Dei and the Fraternity of St. Peter.
It's truly rare to get a glimpse of other Western rites and uses such as this. For those not familiar, the Ambrosian liturgy is associated with church of Milan. (Read more about it in The Catholic Encyclopedia.) For those not as familiar with the liturgical history of the Latin West, you may be familar with the Christian East which has a variety of liturgical rites. The Latin West also had various rites and also "uses" -- variations on the Roman rite. For example, in England prior to the schism of Henry VIII, there where the uses of Sarum (Salisbury), Hereford and York. Likewise, many religious orders had their own variations, the best known being the Dominican and Carmelite. Finally you have also heard of the Mozarabic rite.
This list is far from complete but it does give us a look into the historical precedent and background, besides the even greater living witness of the Christian East, in meshing out a sense of legitimate liturgical diversity, both in theory and in practice, for the Latin West -- legitimate liturgical diversity of course and not liturgical anarchy, or liturgy abused or manipulated towards the service of some ideology.
Those interested in this topic may also want to pick up a copy of the book, Looking Again at the Question of the Liturgy with Cardinal Ratzinger: Proceedings of the July 2001 Fontgombault Conference wherein are found some essays which deal specifically with this question of rites, uses and liturgical diversity.