A Lutheran Ordinariate?

Reports are circulating suggesting the Vatican is open to the creation of a Lutheran Ordinariate- or, more correctly, an Ordinariate for groups of former Lutherans:
From George Conger [here]

"The Vatican is open to creating an ecclesial jurisdiction for Lutherans who wish to join the Roman Catholic Church but preserve aspects of their liturgical and ecclesial patrimony, the president of the Pontifical Council for Promoting Christian Unity has said. In an interview with Zenit published on 24 Oct 2012, Cardinal Kurt Koch said the Vatican would entertain creating a structure similar to the Anglican Ordinariate for Lutherans.
Such a structure was possible due to a convergence of beliefs on certain doctrinal issues, Cardinal Koch said, as progress had been made in the ecumenical dialogue between Catholics and Lutherans in Germany."

More here from Anglican Ink and a more sceptical take from  Fr Z, a former Lutheran himself [here] and here is the ZENIT interview with the Cardinal himself which has given rise to the reports and comment.
One can see the potential theological and ecclesiological difficulties in a reconciliation of this kind - it could be thought that the various traditions and ecclesial groupings of Lutheranism tend to lack the Anglican tradition's (that should also probably read traditions') necessary affirmations or even ambiguities towards continuity with the medieval and patristic Church; but the atmosphere of ecumenism under the 'Pope of Christian unity' is certainly looking radically different.