The World Youth Day 2011 organisers have released the WYD 2011 hymn, Firmes en la Fe (Firm in Faith). It has three versions - one liturgical, one instrumental and then the pop version to get the young people singing. Not a bad idea at all. I am between two minds with regard to this hymn, though.
While we all agree that music for the liturgy must be appropriate, there must also be room for a more popular brand which draws young people into faith. Interestingly if we look at the history of the Church we see that popular ballad type music was a major weapon in the arsenal of a number of heretical movements. Arius notoriously used popular music to promote his theology, and as people sang his songs they came to believe what he preached in the lyrics - that Jesus was only a man. I know James MacMillan has advised we do away with the guitars and bring back sacred silence, and I agree with him, but I think we also have to find a way of including good pop-style music, not so much in the liturgy, but in festive faith gatherings for our young. But, as we know, that is vexed question.
Here is the page with the new WYD 2011 hymn in its various forms (includes sheet music):