Catholic philosopher Michael Liccione has an excellent response here to CNN's Roland Martin regarding the Congregation of the Doctrine of the Faith's "Responses to some questions". Liccione's response is absolutely spot-on, and takes the prize, in my opinion.
Other good responses to the CDF document recognize that it actually advances ecumenical dialogue. My favorite of the five below is Stan Guthrie's, in Christianity Today.
Taylor Marshall's (former Presbyterian, then Episcopalian priest, now Catholic)
Al Mohler's (Southern Baptist)
Metropolitan Kirill's (Russian Orthodox)
Rod Dreher's (former Methodist, then Catholic, now Eastern Orthodox)
Stan Guthrie's (Evangelical)
"Let unity, the greatest good of all goods, be your preoccupation." - St. Ignatius of Antioch (Letter to St. Polycarp)