Rant continues below.
I find it hard to believe that Derbyshire doesn't, as he claims, comprehend the horror at the heart of Huxley's novel. I haven't read the novel since I was in high school, but it left an enduring impression of a future where robots didn't exist because there was no need for them. In the year 632 AF, people had become nothing more than happy robots, meat machines that were built in factory-like birth labs, programmed in their sleep, and as adults went through the motions required of them by their hyper-stratified society until they became too old, at which point they were euthanized. This is not the future most Americans want, no matter what Derbyshire may think. For better or worse, most of us who wake up under the Stars and Stripes are all about the egalitarian, meritocratic society where everyone follows the same rules (pretty much) and there is no aristocracy except the natural aristocracy of merit. That's the ideal we all believe in, and why Derbyshire thinks we'd gladly toss that over for a future of biologically-determined class-ridden sex and drugs with no rock and roll or baseball makes no sense to me.
His reliance on surveys and news media reports to indicate the shrinking size of the Catholic flock also makes me dubious of his conclusions. It's been a long-standing (and undisputed, IIRC) critique of the media that they don't distinguish between bogus "Catholics" like John Kerry and Frances Kissling, ethnic "Catholics" who were raised Catholic but haven't been to Mass since they were teenagers, and the real deal who go to Mass every week and do their best to live the Gospel in spite of all the distractions modern life has to offer. Once you weed out the so-called Catholics who don't practice what the magisterium preaches, the numbers look very different - including the birth rates. I would argue that part of the reason the Church does so poorly in Europe is that for so long it was established in many of those countries, and nothing kills off a religion better than having it associated with the powers that be. I also question his assertion that the African and South American branches of the Church are too syncretic and charismatic to have an effect on the North American and European dioceses; there have been charismatic movements in the First World Church as well, but Derbyshire is evidently neither old enough nor well read enough to be aware of them, nor does he seem aware that Joseph Cardinal Ratzinger has been energetic in applying the smackdown to syncretists and other heretics these last few decades.
My opinion is that it's far more likely that the Church is on the brink of a revival in the First World. Many people are becoming disillusioned with the materialistic excesses of the Baby Boomer generation and turning to conservative religious faiths for answers; it is no accident that the one group of American Jews experiencing a growth in numbers are the Orthodox. There is also the Roe Effect to consider; those prone to a materialist lifestyle often choose to abort their children or not conceive them to begin with, which over time seems to indicate that the number of religious conservatives tends to grow.
So I'm not too worried about Derbyshire's pessimistic forecast. 2537 is a long way off, and brooding over the materialism of my countrymen might lead to despair...which, after all, is a sin. ;P
UPDATE K-Lo (no relation to J-Lo, I'm pretty sure) has some reactions to Derb's essay here, here, here, and finally here.