I think there's way too much to expect a response so quickly. I think a lot of people aren't sure how to react to it just yet. If you just see it as "something the Pope wrote about the environment," then the point is lost, as he even states in the letter. But as someone not Catholic, looking at what is going to happen with this letter, perhaps there's an aspect to Pope Francis' role that may not be seen outside the faith:
Many people outside the Catholic faith see the Pope as the figurehead of the faith, and that we as Catholics assume that the Pope is our current leader. Rather, the role of pope, the Servant of the Servants, is chosen among the other cardinals to represent the leadership and guidance of the Church here on Earth. The Catholic Church attempts to address various aspects of the human condition in our attempt to live out the Gospel, and yet our lives are always changing with the world around us. Part of the role of the Pope is to see these things, and with prayer and discernment, attempt to provide direction to a Church that spans many nations and has a history of over 2000 years.
In the past, Blessed John Paul II and Benedict XVI were more identified with discussions that "appeared" to be more conservative. I use quotes because both popes had strong messages regarding capital punishment and immigration that do not fit into a conservative/liberal framework. However, it seems that the former was more identified with the previous Popes.
In the time that Francis has served as Pope, we have seen an undeniable focus in a different direction. Francis of Assisi heard the call to "Rebuild my Chuch," and in many ways this could be the tagline for Pope Francis. He has not waivered from the values of previous popes regarding abortion, sexual ethics, governmental exploitation. However some of his words and his actions now challenge the constructs of conservative/liberal frameworks, especially in the United States. There are many theories and discussions regarding this, but the point is that there are a number of Catholics who honestly don't know how to feel. What they are hearing from the leadership of their faith challenges some values and ideas that they've grown up with, and some news venues either praise Pope Francis for being green or accuse him of being a Communist.
For the Christian, we are always called to conversion; in our thoughts, actions, and what we say and do. This encyclical is a pretty big deal. I think some Catholics are going to need time to come to terms with what they are being asked.
I've been reading it over the past few days and I'm still digesting the text. If there's one soundbite immediately, I think its the fact that Pope Francis is calling for all of us, not just Catholics or just Christians, but all of us to recognize that we are caretakers of our common home and all that has been created within...from the Earth to the poorest of the poor who are most affected by the current climate changes we are facing today.
I don't know if that's what you wanted to hear about Laudato Si, but I think just looking for the "Catholic Response" falls short of the point that Pope Francis is trying to make. =)