In limited circumstances, and only to fight HIV.
The pope signaled a new direction in the church's fight against HIV today by suggesting that condoms can be a legitimate way to prevent infection if that is the sole intent–in other words, not for birth control: "The Catholic Church is not fundamentally against the use of condoms," he said in a soon-to-be-available book-length interview, as quoted in the UK Telegraph: "It of course does not see it as a real and moral solution."
I think anyone who wants to tame the HIV epidemic will be happy to hear this news. Since Catholic agencies provide up to 30 percent of medical care in developing parts of the world, they will be freer to employ the ABC model (abstinence, being faithful, condoms) that many see as the gold standard.
The pope also blows a hole in the "intrinsically evil" approach to condoms used by some Catholics to rule them out in all cases. B16 has explicitly invoked intention by arguing in favor of condom use in certain circumstances–including the situation of prostitution. The question now is whether he or others will extend that consideration to other situations, say the case of a woman whose physician has counseled her against becoming pregnant for health reasons. Moral theologians will be quick to ask whether condoms can also be employed to prevent the spread of other sexually transmitted infections, even if they will not cause death.
Also up in the air is whether the pope or a Vatican congregation will issue a teaching document that would memorialize the shift. Right now it will appear only in a book-length interview–in other words as it stands this is just an expression of the pope's personal opinion. I at least do not see it as an official act of papal magisterium. So I hope that in the next year we will see something more official.
The person I think gets the most credit for pushing this conversation forward–and he may well be forgotten–is Bishop Kevin Dowling of Rustenberg, South Africa, who has stuck his neck out for years lobbying for this new approach. For anyone out there who doesn't believe in doctrinal development, this is how it happens.