And the concept of "optional celibacy" is wholly and entirely alien to historic Christianity. No Apostolic church, Catholic, Orthodox or Monophysite permits priests to "choose" a mode of life after ordination. Once one is ordained one is confirmed in his state of life: those married before ordination must remain married, those unmarried before ordination must remain celibate.
That's the way it has always been in every church that traces its succession back to the Apostles.
I see nowhere in this letter (a more complete story is on the News/Activism forum) that these priests are asking for marriage for themselves.
It's also interesting that Dolan did nothing to stop the release of this letter, nor will there be any fallout for the priests who signed it.
If mandatory celibacy is as strong as many think it is, then it would certainly survive some spirited discussion, which seems to be what Dolan is thinking.