Tomorrow, the Solemnity of the Body and Blood of Christ, I will preside at Holy Mass at seven o’clock in the evening, in the square of the Basilica of Saint John Lateran. Afterwards our traditional procession to Saint Mary Major will take place. I cordially invite all of you to join this celebration where we give witness together to our faith in Christ, present in the Eucharist.
On the calendar according to the 1970 Missal (Novus Ordo), the Solemnity of the Body and Blood of Christ is on the Sunday following Trinity Sunday. It was formally celebrated on the Thursday after Trinity Sunday on the traditional calendar, as this this link states. I wonder if the Holy See has kept the traditional date, or if this is something Pope Benedict has decided to do. If it is something that he decided to do, it is a good sign for traditionalist Catholics.
Speaking of the traditionalist Catholics, most would be familiar with a verse from the Psalm that Pope Benedict reflected upon at this audience (Psalm 115).
Quid retribuam Domino pro omnibus quae retribuit mihi?calicem salutaris accipiam et nomen Domini invocabo.
What return shall I make to the Lord for all He has given me? I will take the chalice of salvation, and I will call upon the Name of the Lord.
The priest says these words after he receives the Body of Christ, and right before he receives the Precious Blood of the Lord.
Perhaps the ordo you referenced is only for the US? Maybe the Vatican has kept the observance on Thursday. Italy, I believe, will be observing Corpus Christi on Sunday when Benedict XVI will be celebrating the closing Mass of their Eucharistic Congress.
I noticed that, too. I wish they'd go back to those mid-week celebrations on the day itself - putting them all on Sunday essentially makes them disappear, which of course is probably what the folks behind this really wanted, anyway.
I think it's also a very important witness for people to see Catholics celebrating feast days on their own calendar. Having a public Corpus Christi procession on a week day makes an impact - heck, having alternate side of the street parking suspended in NYC so that Catholics could go to Mass on weekday Holy Days of Obligation also made an impact. It made the Church and its liturgical activities noticeable, rather than making it look as if we do everything possible to accomodate ourselves to secular schedules because our own practices really aren't that important after all.
I checked out the Vatican site for Papal Office for Liturgical Celebrations and checking the archives, looks like, at least from 2000 to 2004, the Solemnity was celebrated on Thursday.
A lot of holy days were moved or abolished by the episcopal conferences with the authority they have in Canon 1246.
I imagine the Vatican is not part of any national conference so they set their own calendar. And they probably have a higher percentage of parishoners willing and able to fulfill a mid-week obligation.