Why is Pope Benedict Cautious As To Recent Muslim Overtures?

Last month there was quite a bit of buzz worldwide by " the Letter of the 138 Muslims" that was addressed to Pope Benedict and the heads of the other major Christian Communities. I think it was significant event.

However some people were curious why the Vatican did not respond in a more robust manner to this development. Leading Muslims are asking for dialogue and the Holy Father/The Vatican response SO FAR is measured. What gives? I think the Chiesa has a very good and insightful article on perhaps the reasons why at Why Benedict XVI Is So Cautious with the Letter of the 138 Muslims. A another good read.