The polemic here is all a tad over the top. See The faithful torn apart from the UK Telegraph.
There is a tendency to write this up in the UK press as something akin to a James Bond novel. I am pretty confident that the Church of England knew what was coming it's way. The article does hint at the real cause for not making all this public with daily press releases. That is the opposition by some in the Vatican and some Catholic Bishops. After all the Catholic Bishops pretty much ignored in many cases the Pastoral Provision which actually brought some Anglican /Episcopal Churches in the USA into the Catholic Church . So they really had no choice. Still we had so many false alarms in the past that everyone knew this was close .
Further we are not just talking Church of England here. While the Archbishop of Canterbury might be the symbolic head it is not really clear if the true head that is running the Anglican communion is the Primate of Episcopal Church USA. One cannot ignore how actions of the American Episcopal Church was pushing the entire Anglican Communion into new areas. So there was a concern and indeed Anglo Catholics asking for this WORLDWIDE.
In the end I do not think there will be huge defections. Most of the growth in this new structure will come from people already Catholic and indeed from converts.