UPDATE: The spokesman, Fr. Lombardi, was right on the spot, it seems:
You knew this had to happen.
From Alessandro Gisotti of Vatican Radio (my translation):
To a question about politicians in Mexico who supported the law to decriminalize abortion, the Pope underscored the necessity of coherence for Christian politicians, repeating that the Church announces the Gospel of life: "Life is a gift, not a threat."
The director of the Press Office, Fr. Federico Lombardi [who just happens also to be the director of Vatican Radio] commenting on some news flashes about the Pope’s response clarified that since no excommunication was declared on the part of the Mexican bishops neither did the Pope mean to declare one. The legislative action favoring abortion, Fr. Lombardi said, is not compatible with participation in the Eucharist. "So are they excommunicated?" he was asked: "No", Fr. Lombardi clarified, "they have excluded themselves from Communion."
"’Ma sono dunque scomunicati?’, gli e’ stato chiesto: "No – ha precisato padre Lombardi – si autoescludono dalla Comunione".