"How do we reconcile the treasure of the liturgy in all its solemnity with the sentiment, emotion and excitment of masses of young people called to participate in it?"(That's "masses of young people", not "Masses of young people".)
The Pope eventually whittled the question down to its core, as to whether these enormous Masses with hundreds of concelebrants and thousands upon thousands of faithful receiving Holy Communion are "the structure the Lord wanted". In Fr. Z's words: "[A]re these mass Masses a good response to the reality of large crowds who want to be with the Pope? Should Communion and concelebration, perhaps, be more limited?"
Does the Pope have a solution? Not yet, but he does have a plan of action:
[T]here is the solution, for now only partial, but nevertheless necessary, in view of the upcoming ocean-sized Masses: for two occasions on the apostolic visit to the United States (on 17 April in the new Nationals Park and 20 April at Yankee Stadium in New York) and those foreseen for World Youth Day in Sydney. In the USA and Australia, the Pope decided not to delegate any longer the organization of celebrations to third parties. And so he asked that, in the next days, that his Master of Ceremonies, Msgr. Guido Marini, should fly across the oceans (both the Pacific and Atlantic) with the precise task of studying the locations to be used for the liturgical functions with the end of taking on direct responsibility for carrying out celebrations in those spaces; that the result might be Masses that are as vast as oceans, but at least characterized as much as possible with composure and discipline.[Source: WDTPRS]