From a purely juridical standpoint nothing better has been written on Pope Francis’s motu proprio Mitis Iudex Dominus Iesus than Dr. Edward Peters’s two entries (here and here) at his canon-law blog. I don’t know if I can recommend any other reading on the matter in good conscience, simply because so much of what has been written in the Catholic press borders on absurd. “Prudent reforms”; “Nothing has changed”; “Doctrine remains untouched,” and so on and so forth. Of course doctrine has not been touched in any direct manner; it’s just now Catholics will likely have a much easier time circumventing it.
If a silver lining is to be found amidst this fresh storm of confusion to hit the Church, let it be this: No Catholic should any longer strike a triumphalist posture against the Eastern Orthodox with respect to the latter’s marriage praxis. Orthodox doctrine may not be exactly “neat” in this area, but they have dodged the need to engage in legalistic acrobatics to justify their behavior. I hope that charity compels the Orthodox not to snicker too loudly over all of this. When it comes to the crisis of modern marriage, we’re in this together.