I saw this list at io9, and figured, just for the exercise, to go through Heinlein's predictions one by one and see what The Dean got right and wrong...
1. Interplanetary travel is waiting at your front door — C.O.D. It's yours when you pay for it. Wrong! I'm just as disappointed as you, Rob.
2. Contraception and control of disease is revising relations between the sexes to an extent that will change our entire social and economic structure. Correct! The Sexual Revolution was practically on America's doorstep in 1952, so it wasn't hard to get this one right.
3. The most important military fact of this century is that there is no way to repel an attack from outer space. Mostly wrong! Attacks from outer space, no. But satellite surveillance to gather intelligence is an important military factor, and we do have our robot drone planes. But I'm pretty sure that Heinlein had in mind rocket ships with missiles raining down from the void. He's wrong, thank Cthulhu.
4. It is utterly impossible that the United States will start a "preventive war." We will fight when attacked, either directly or in a territory we have guaranteed to defend. Wrong! Ha ha ha ha ha, Rob, how naive you were about politics in the 1950s!
5. In fifteen years the housing shortage will be solved by a "breakthrough" into new technologies which will make every house now standing as obsolete as privies. Wrong! But it's hard to imagine what he had in mind. Housing technology has continued to improve, but the "housing shortage" was always a matter of economics - we have plenty of homes, but they're all sitting empty and rotting while banks own them all.
6. We'll all be getting a little hungry by and by. Wrong! Malthusian predictions about running out of food are always wrong. If anything, we have a problem with obesity. And don't tell me about third-world orphans starving - that, again, is politics - there's plenty of food, but also plenty of dictator idiots causing famines.
7. The cult of the phony in art will disappear. So-called "modern art" will be discussed only by psychiatrists. Wrong! Sorry you were so grumpy about art, old guy, but "modern art" wasn't even close to its peak yet at the time you wrote this.
8. Freud will be classed as a pre-scientific, intuitive pioneer and psychoanalysis will be replaced by a growing, changing "operational psychology" based on measurement and prediction. Wrong! Also, huh? Psychoanalysis has changed some since the 1950s, but what has largely replaced such treatments is pills, pills, pills, pills, pills.
9. Cancer, the common cold, and tooth decay will all be conquered; the revolutionary new problem in medical research will be to accomplish "regeneration," i.e., to enable a man to grow a new leg, rather than fit him with an artificial limb. Wrong! We're so, so sad to say so. But stem cell research is looking into that whole "regeneration" thing.
10. By the end of this century mankind will have explored this solar system, and the first ship intended to reach the nearest star will be a-building. Wrong! No human has yet set foot on anything but Earth and the moon.
11. Your personal telephone will be small enough to carry in your handbag. Your house telephone will record messages, answer simple inquiries, and transmit vision. Mostly Correct! In fact, this one almost sounds too specific to have been in this list - did somebody add this one? Substitute "computer" for "telephone" for those last two.
12. Intelligent life will be found on Mars. Wrong! In fact, it's growing doubtful that we'll find anything alive on Mars, even fuzzy little microbes.
13. A thousand miles an hour at a cent a mile will be commonplace; short hauls will be made in evacuated subways at extreme speed. Wrong! Not even sure how he thought this would happen - had he never heard of G-forces? But so far the fastest land-speed record is 760 MPH with a turbofan at Black Rock Desert in 1997, and that's far from "commonplace" or cheap.
14. A major objective of applied physics will be to control gravity. Wrong! No, no, no.
15. We will not achieve a "World State" in the predictable future. Nevertheless, Communism will vanish from this planet. Wrong! Communism is alive and well, thank you. And as for "world state", the United States is just about as close to a world empire as we've gotten. McCarthy much?
16. Increasing mobility will disenfranchise a majority of the population. About 1990 a constitutional amendment will do away with state lines while retaining the semblance. Wrong! What a Libertarian. While we'd grant that transportation advances have killed off many industries, dozens of new industries have sprung up to take their place.
17. All aircraft will be controlled by a giant radar net run on a continent-wide basis by a multiple electronic "brain." Correct? We could consider computerized air-traffic control systems to be this. The Internet is certainly continent-wide. We even came up with much better tracking methods in the form of telemetry.
18. Fish and yeast will become our principal sources of proteins. Beef will be a luxury; lamb and mutton will disappear. Wrong! Our plates are still full of every kind of meat we can imagine. Australians are the only ones who even took to that yeast thing.
19. Mankind will not destroy itself, nor will "Civilization" be destroyed. Correct! Well, I guess if this weren't true, we wouldn't be here to say so.
Here are things we won't get soon, if ever: Travel through time, Travel faster than the speed of light, "Radio" transmission of matter, Manlike robots with manlike reactions, Laboratory creation of life, Real understanding of what "thought" is and how it is related to matter, Scientific proof of personal survival after death, Nor a permanent end to war.
Time travel, check, FTL, check, Life-after-death, check, No-end-to-war, check. Understanding-of-thought is too debatable to even decide on, but check. But we do have 3D printers which transmit the <em>data</em> to another machine which builds matter into whatever part was ordered, so half-point? We do indeed have "manlike" robots with the Honda ASIMO, but it has nowhere close to human reactions. Laboratories are at least doing fantastic things with DNA and stem cells - they haven't turned inorganic matter into living matter yet, but they're getting damned close.
In all, Heinlein seemed to suffer from the kind of short-sighted vision of continued scientific enthusiasm that affected every American in the 1950s; this was the age of zeerust, after all.