Well, apparently, this is a more complicated matter than I thought. Here is what one Orthodox Bishop has to say about the subject:
It would seem that the Liturgy of the Presanctified Gifts would have one and the same meaning both for the Greeks and Russians. The people like that service and many do attend it, especially if it is celebrated in the evening, as it should be, although this "daring novelty" still meets up with strong objections and is not widely practiced, except among the Orthodox in the West. But even if there are no observable differences in the celebration of the Liturgy of the Presanctified Gifts, which could impact upon the spiritual experience of the people, still there are some serious theological differences, although not officially formulated, which underline the actions and words of the celebrants behind the iconostas.
Here (to the great surprise of many lay people and even the clergy that do not even suspect it) arises the question: does the wine in the chalice, during the Liturgy of the Presanctified Gifts, change into the Lord's Precious Blood, as it does during the Liturgies of John Chrysostom and Basil the Great, or does it remain what it was, except that it was blessed and sanctified? The Russian Liturgy, since the time of Peter Mogila in any case, answers in the negative: the wine is not changed. This understanding is demonstrated by the fact that the celebrant partaking of the presanctified Body of Christ, which was intinctured with the Precious Blood sanctified at the Liturgy of Chrysostom or Basil the Great, drinks from the chalice without pronouncing those words, which he would when partaking during a "full" Liturgy. Furthermore, if he is celebrating without a deacon and would later consume the remaining Gifts by himself, he does not drink from the chalice. The deacon that would consume the remaining Gifts at the end of the Liturgy never drinks from the chalice even when he receives Communion. To drink from the chalice is viewed as an impediment towards consuming the remaining Gifts, as is explained in the "Notes concerning certain procedures for the celebration of the Liturgy of the Presanctified Gifts," which go back to the time of Peter Mogila: "If the priest is celebrating alone . . . he does not drink from the chalice until the end of the Liturgyþ Even though the wine is sanctified by the placing of the particles (of the sacred Body), it is not transubstantiated into the Divine Blood, since the words of institution were not pronounced over it as occurs during the Liturgies of Ss. John Chrysostom and Basil the Great." This same opinion is expressed in the Russian Church's practice of not admitting infants to communion during the Liturgy of the Presanctified Gifts since, because of their age, they are unable to swallow a particle of the Body of Christ and the wine is not considered to have been changed into the Precious Blood. The Greek practice, as indicated in the service books, although not too clearly, presumes what appears to be completely different theological beliefs. Concerning the Liturgy of the Presanctified Gifts it briefly states: "The priest partakes . . . of the Sacred Gifts just as during the Liturgy of St. John Chrysostom." Meaning that, as he drinks from the chalice he says: "The precious and sacred Blood of our Lord and God and Savior Jesus Christ is given to me..." Thus, what is in the chalice is considered to be Christ's Blood. This is supported by the practice of drinking from the chalice three times, just as at the Liturgies of Chrysostom and Basil the Great, which would not have been of much significance if this was said just about wine and not the Sacred Blood. After all this the celebrant consumes the Sacred Gifts as during the usual Liturgies. As for the theological explanations, we can find these in the Byzantine liturgists beginning with the 11th century: during the placement of the particle of the Body of Christ into the chalice the wine changes into the Precious Blood of the Lord through contact with His Body.
I will not express myself concerning this serious theological question. To form a decision about this difference (if indeed it exists, since one cannot make firm conclusions on the basis of different practices what concerns differences in belief) is beyond my competence since the Church, neither in Byzantium nor in Russia, adopted any conciliar decision on this account. I will only note that the explanation for the change of the wine into the Blood of Christ through contact with a particle of the Body appears strange to me and is unknown to the ancient Fathers. As for Peter Mogila's "Note," it is obviously inapplicable because of its Scholastic terminology ("transubstantiation") and its non-Orthodox theology according to which, the Epiklesis is replaced by the words of institution during the sanctification of the Eucharistic Gifts.
The publishers of liturgical books in Russia understood this well: although they include Peter Mogila's "Note" in the text, its more shocking segment, which we cited above in part, is shown in brackets. On the other hand, the theory of the change through contact carries with it a similar defect: it leaves no place for the Epiklesis. As for the Russian practice, it appears to be more correct but is contradictory in that it prescribes that the celebrant drink from the chalice three times (does it have any particular meaning if this is not the Blood of Christ?) And yet it is excessive in that it forbids him to drink if he is the sole celebrant.
by Archbishop Basil Krivoshein, Archbishop of Brussels and Belgium
from a report given at the Liturgical Conference at the St. Sergius Theological Institute, Paris, on July 2, 1975
Here is a link to the entire article: http://www.holy-trinity.org/liturgics/krivoshein-greekandrussian.html
Apparently there is a divergence here between the Greek and Russian tradition, one that an Ecumenical Council has not resolved.
This is interesting.