1962: "O God, Who willed that, under the special patronage of the Blessed Virgin Mary, we be laden with perpetual favors, grant to Your suppliants that, as we this day rejoice in her commemoration on earth, we may enjoy the vision of her in heaven. Through Jesus Christ...
2000: "O God, Father of mercies, who placed your people under the singular protection of your Son's most holy Mother, grant that all who invoke the Blessed Virgin of Guadalupe may seek with ever more lively faith the progress of peoples in the ways of justice and of peace. Through Jesus Christ..."
Omitted: "Laden with perpetual favors..."
Changed: From "Grant...that, as we this day rejoice in [the commemoration of the Blessed Virgin Mary] on earth, we may enjoy the vision of her in heaven" to "Grant...that all who invoke the Blessed Virgin of Guadalupe may seek with ever more lively faith the progress of peoples in the ways of justice and of peace."
So the prayer was changed to eliminate the talk of the gifts of God already received and enjoyed through the intercession of Our Lady, the rejoicing in her on the earth, and the glory to be revealed in heaven, in favor of a social gospel to tell ourselves that we need to work more for peoples' progress and for justice and peace.
This contrast between the prayers seems to say, "Don't worry about giving us heaven, just make us work more on the earth," (albeit "with ever more lively faith," whatever that is supposed to mean, while eliminating the acknowledgment of the gifts of God on earth and the hope for the same in heaven).
This preference for "the ways" of peace and justice on earth over the present joy of faith and the hope for eternal rewards smacks of Marxist ideology. Secular humanism has surely infected our sacred rites.
Cf. "Karl Marx took up the rallying call [of secular humanism]...towards what Kant had described as the 'Kingdom of God'. Once the truth of the hereafter had been rejected, it would then be a question of establishing the truth of the here and now. The critique of Heaven [of Kant] is transformed into the critique of earth, the critique of theology [again, of Kant] into the critique of politics--from a scientifically conceived politics that recognizes the structure of history and society and that points out the road towards revolution, towards all-incompassing change." Spe Salvi, 20.