(originally intended for this thread: http://www.orthodoxchristianity.net/forum/index.php/topic,34682.0.html
but I decided to start a new thread so the old wouldn't get derailed.)
Sometimes I wonder if we legalize the "communion" process a bit too much. (and before I get jumped all over let me explain myself)
It seems to me that the Oriental Orthodox themselves weren't formally anathematized. The split materialized over time, and exists for reasons other than the declaration of a council.
As for Roman Catholicism, the schism also materialized over time, but there were many councils called denouncing the "Latins" (as they were known) and their various beliefs and practices. But there was about 150 years between the incident in 1054 and the 4th Crusade in 1204 where there were still concelebrations and where it was kind of a grey area as to the status of the schism.
From my perspective, union between Oriental and Eastern Orthodox may be kind of similar. We will probably see concelebrations, declarations, councils, etc... between the two, but there may not be a single council that massively declares a reunion.
On the other hand, I would say that with the EO and RCC, it's not quite that simple.
The famous and oft quoted canon comes from the Apostolic Canons.
65. If any one, either of the clergy or laity, enters into a synagogue of the Jews or heretics to pray, let him be deprived and suspended.
“Let any clergyman or layman who enters a synagogue of Jews, or of heretics, to pray be both deposed and excommunicated.” Apostolic Canon 65.
Would oikonomia be applicable in a situation where two groups are genuinely close? Is it not possible for two churches to be unified without a single central council? (though multiple councils should definitely reinforce it)