"At a Mass celebrated by the Bishop or at which he presides without celebrating the Eucharist, the norms found in the Caeremoniale Episcoporum (Ceremonial of Bishops) should be observed."
"A change in a matter of such moment, based on a most ancient and venerable tradition, does not merely affect discipline. It carries certain dangers with it which may arise from the new manner of administering Holy Communion: the danger of a loss of reverence for the august sacrament of the altar, of profanation, of adulterating the true doctrine..." - MEMORIALE DOMINI
Prominent among the problems is the decision of the translators to break with common Catholic usage and translate the Latin "presbyteri" into English not with "priests" but with "presbyters". This cannot meet with the Holy See's consent since it risks being misunderstood by the people and represents an unacceptable theological tendency. In particular it constitutes a retreat from a term that carries a sense of sacrality, that carries with it the history of the development of the faith in favor of a term which does not.
The full letter can be read here.