dictate nothing to any given church; that's up to the pastor/reverend/priest/whatever. The Toronto Metropolitan Church has been willing to hold "marriage ceremonies" for gay/lesbian couples for years, minus the "power vested in me by the ... government of Canada" and signing the registry parts. They can add them back in now when marrying same sex couples.

I personally doubt very much that you're going to find many gay marriages down at the local Catholic or Anglican cathedrals... but saying that there's no state dimension to marriage is completely bogus when you consider the huge ramifications it has for taxes.