The idea that the Pope is going to play nice with the Nones, especially atheists, is a bit far fetched. I will be pleasantly surprised if he lives up to his rhetoric. Alessandro Speciale's Religious News service piece (reposted on HuffPo), "Pope Francis: 'Nones' Can Be 'Allies' For The Church", seems to take it as a foregone conclusion. He may not have had a hand in how this short article was titled but I'm sure he saw it before it got put out. The title does give a hint as to the motivation. I'd point out that it states that Nones can be allies to the church rather than vice-versa.
I do not assume that Pope Francis is sincere. In fact, I assume the opposite. If he really wants to make friend with atheists he could start by apologizing for his predecessor. Benedict in a handful of speeches blamed atheists* and secularist for the worlds cruelty and injustice. He could really take a positive step by pledging that the church will stop demonizing non-believers. I have been to plenty of masses and can remember numerous occasions where "non-believers", "unbelievers", "the faithless", etc.. were used as pejoratives. Somehow I do not think that is going to happen.
Basically, he's looking to spruce up the Church's image.
*It is important to note that he specifically chose the term atheist(s) rather than atheism. In other words, he was attacking the people not the ideas.