I'm back now, having spent a few days in the Eternal City with family. On Monday, I bumped into Fr Uwe Michael Lang in St Peter's Basilica. I gather that he has been given a new job in the Congregation of Rites. I am sure he will do very well there.
I also heard, from another source, that the document on the interpretation of the Holy Father's Motu Proprio on the traditional Mass went to the Pope's desk for approval shortly after Easter. How long it'll take to make its way back to the publishers is another matter. I'm afraid I heard nothing about the document's content, however.