Fr John Zuhlsdorf writes an excellent blog from Rome called What does the prayer really say? He writes on various liturgical topics and has an extensive Patristic Rosary Project in progress.
He has written before on the question of the pro multis and recently referred to the rumours I mentioned in his post About "pro multis". (He felt that it may have been imprudent for me to mention them and if this is so, I am sorry.)
In one post, he has collected together links to his thorough articles on "pro multis". They are well worth reading for some comprehensive background on this issue.