I too had the feeling that this recent kidnapping and forced "conversion" had something to do with his remarks. He probably believes that if he just lets it slip by, it's going to become more common, and I think he's right. This was perhaps a preemptive strike. Not that the Muslims will get it or care, I'm afraid.
I just came across an interesting article on this:
http://www.centredaily.com/mld/centredaily/news/15528996.htm
Excerpts:
The speech suggested deep dismay over the current conditions of Christians in the Middle East and the rest of the Muslim world, said John Voll, director of the Center for Muslim-Christian Understanding at Georgetown University in Washington.
"This reflects the intention of Pope Benedict to distinguish himself from his predecessor on his approach to interfaith dialogue," said Voll. "And by this, it means more reciprocity."
Voll said the pope may increasingly instruct Vatican envoys to stress issues of forced conversions of Christians and limits on Christian rights and worship...
The Rev. Robert Taft, a specialist in Islamic affairs at Rome's Pontifical Oriental Institute, said it was unlikely the pope miscalculated how some Muslims would receive his speech.
"The message he is sending is very, very clear," Taft said. "Violence in the name of faith is never acceptable in any religion and that (the pope) considers it his duty to challenge Islam and anyone else on this."