I have been taking catechism classes at a Greek Orthodox Church. My priest said that the current division between the Eastern Orthodox Church and the Oriental Orthodox Church (Coptic, Armenian, Syriac, Ethiopian, Eritrean, and Malankara) is a great tragedy, and that the division really occurred because of problems in language and semantics, and that there is no substantive difference in Christology. The Chalcedonians feared the Orientals were Monophysites (which they have always denied - they say they are Miaphysites), while the Orientals feared the Chalcedonians were closet Nestorians (which they have always denied).
Both sides now seemingly recognize that each position presents a correct view of Christology, even though it uses a slightly different formula / set of language to describe it.
Now if there are significant numbers of people on both sides who believe there still is a substantive difference in Christology, then let me know who these parties are. However, if the vast majority on both sides concede there is no substantive difference in Christology, why some 1550+ years after Chalcedon, are we not united? Our Coptic brothers and sisters in Christ are being persecuted in Egypt, and yet we are not in communion with them. Seems tragic to me. What's the hold up!?