I am quite surprised that no conspiracy theorists have put forward the notion that this whole retirement of Concorde is one huge marketing campaign to fill the plane up - and that come the second week in October (after which people can't get a refund on their tickets due to the new fare rules) that they will announce that they have found a way to keep it flying for another year etc.
The main reasons cited for withdrawal are falling ticket sales and increased maintenance costs.
This retirement campaign seems to have solved the first problem.