Hi. I'm new, so hope this goes OK. To all those who have been speculating on Latin pronunciation, a few short observations. 1. The pronunciation with hard C is the Classical pronuncation. 2. The Classical pronunciation began a modification process (similar to the self-modification process that changed Middle English to Modern English in the 15th century) about the beginning of the Common Era, or about 1 BCE / 1 AD and continued over a couple hundred years. 3. After this process, Latin had a somewhat different pronunciation in which C was soft (i.e., like ch in church) before I and E and the diphthong AE, hard (like K) before A, O, U and the other diphthongs; along with other changes, principally in the pronunciation of diphthongs -- AE (pronounced like eye in Classical Latin) became either eh (short) or like a in hay (long). Hence, the famous phrase "Caesare certior facto" was pronounced in late Latin Chesare chersior facto. 4. This is the pronunciation used all over Europe, with some minor variations in some areas, during the dark ages and through the Middle Ages right up past the Renaissance. It is still in use in the Catholic Church, and is actually spoken today in the Vatican, since this became what is known as "Church Latin". 5. Do we really know how Latin was pronounced 2000, or 1000 years ago? Yes, we do. There were innumerable scholars (and pseudoscholars) employed as rhetors, orators, and teachers of rhetoric (St. Augustine was one)and some of them wrote books. Needless to say, correct pronuncation was covered in such teaching and some has survived. The current (i.e., Late Latin) pronuncation survived on its own; the old (Classical) pronuncation was preserved in earlier teaching texts, and it was those which gave rise to the revival of the Classical pronunciation which we all learned in Latin I in high school or college.
Sorry for the length of this, but maybe it answers some questions. Also demonstrates (at least I think) that the reports of Latin's demise are as erroneous as those of Mark Twain's.