From the blog of Andrea Tornielli (Vatican correspondent for Il Giornale):
I have learned from secure sources that, contrary to what has appeared in certain articles, the response of the Fraternity [of Saint Pius X - FSSPX/SSPX] to the letter of Cardinal Castrillón has not in fact been negative. The Cardinal is satisfied with it, has responded to Fellay, and has promptly delivered the letter of the Fraternity to Benedict XVI. After the deadline of the end of June, the Lefebvrists [sic] ask for time but - it seems - they will aim to respect the five points.
HT Barbara Kralis