Someone should tell these people

not to get their hopes up (Guardian, via CWN).  Until they understand that Catholicism is a deontological religion, not a consequentialist one, they will not understand why the Church cannot approve of contraceptive sexual activity for any reason.  Perhaps they do not realize that the Church condemns as sin all genital activity that because of its nature (and not because of accidental circumstances such as the woman being out of a fertile period) is closed off to the generation of life.  And that she does this because such is contrary to human nature and displeasing to God, and not because it might in some circumstances have harmful effects on bodily health.  Corporal goods are goods, but they do not take precedent over the good of the soul. 

Worldly pragmatists who style themselves and those who agree with them as "realists" have two barriers to their understanding: first because they are worldly, and secondly because they are consequentialists.  Being worldly, their worldly dogmas preclude them from conceiving of spiritual realities, except as metaphors ordered to some ultimately worldly purpose - the reverse of us, who see that our bodies make visible spiritual realities (cf. Pope John Paul's Theology of the Body).  They even ignore the spiritual degradation of the person caused even in this life by contraceptive sex. Further, being consequentialists, they think that if you can avoid consequences (well, the obvious ones, at least), then that has the same consequences as abstinence, so they consider them to be morally the same thing.  They keep hoping that maybe if someone invented the ultimate condom, then the Church would approve.  They can't understand that the Church disapproves not because the failure of the device is sometimes destructive to the body but because either way its use is destructive to grace in the soul.

The worldly consequentialists don't understand that even the guys with funny hats in Rome really do feel sorry for married people stuck in a tough situation, because they know that not everyone is called to celibacy like they are.  But they also know that to be true to Christ and to teach people to be true to Christ they cannot counsel people to sin that good may come of it, even that the good of the privileges of marriage may come of it.  Sometimes in order to perservere in the Christian life, a heroic sacrifice is necessary.  What about the martyrs?  Should we have counseled them to deny the faith in order to gain the good of longer life?  What about people who want to marry but cannot?  Should we counsel them to have illicit sex so that they don't "miss out"?  Of course not.  But the senseless cannot know this, and the fool cannot understand.  Utterly senseless in his lack of understanding of the life to come, the foolish man insists that all pursue maximum pleasure and minimum suffering in the here and now as the highest good.

As a final note, one might remember that the Anglican communion has already done us the favor of volunteering as a laboratory for any number of bad ideas, so that we don't have to "what-if" about these things.  I say this with grim irony because unfortunately, the bad results were not confined to an "It's a Wonderful Life"-like imaginary alternate future.  Perhaps you know that before the 1930 Anglican Lambeth Conference caved in and approved birth control for those in "extraordinary circumstances" for "grave reasons," all Protestants were against it.  As there was no objective basis for the definition of those "extraordinary circumstances," but only sentiment, it was soon overwhelmed and replaced by approval of contraception-on-demand for any reason, and virtually all Protestants followed suit.  Only by a strong exercise in wishful thinking can one fail to see the dissolution of society that has resulted.

If the prohibition of contraceptive sex was a matter of the positive law of the Church*, then people could conceivably (ha!) receive a dispensation to do it, particularly for some good reason, like fostering the "unitive" aspect of marriage.   However, it is a point of natural law that cannot be done away by the fiat of the pope.

*Example: At one time we were required to abstain from eating meat on Friday (and still are during Lent).  Doing so on purpose was a mortal sin not because there was anything in the combination of meat and Friday that was objectively evil or contrary to human nature, but because of the disobedience to the rightful authority of the Church who had posited the law for the benefit we would receive from this simple act of ascesis and obedience.  However, dispensations could be granted for a good reason; and ,when in the Church's judgment the burden outweighed the benefit, the law was able to be done away with since it was indeed an arbitrary positive law.  However, the Church could not ever and does not have the authority to dispense from, say, the prohibition of adultery, or do away with the Sixth Commandment, because this is not an arbitrary law made up by the Church, but rather part of the natural law (see earlier posts on this topic).  Just so you understand the difference.