From Catholic World News:
Regarding the sensus fidelium, which is frequently invoked to justify calls for change in controversial Church teachings, the Pope reminded his audience that the term refers to “a kind of supernatural instinct” among the faithful. He underlined the importance of this sense, quoting the Vatican II document Lumen Gentium: “The entire body of the faithful, anointed as they are by the Holy One, cannot err in matters of belief.”
However, the Pope said, the sensus fidelium presumes a deep attachment to the faith, and cannot be reduced to a matter of prevailing public opinion. He continued:
And it is unthinkable to mention it in order to challenge the teachings of the magisterium, this because the sensus fidei can not grow authentically in the believer except to the extent in which he or she fully participates in the life of the Church, and this requires a responsible adherence to her magisterium.
I've seen too many people misuse the idea of sensus fidelium to justify their actions - I have been guilty myself. I'm glad to see the Pope Benedict address this issue.
Pax et bonum