Visions of the Future, Courtesy of Herbert

There's so much to talk about with Dune. The obvious parallels to our own world already mentioned by Professor Jackson, the differences between the Fremen and the rest of the population of the empire, the religion. But I'm not going to talk about that. Instead, I've found a few other things.
First off, the Bene Gesserit. I've always thought they were pretty cool. This group with it's claws in just about everything. Semi-mystic, so they took the cloak of religion when they went out into the empire, laying the groundwork on Arrakis that Paul took advantage of, though Jessica used it first. This groundwork was put in place for the sole purpose of exploiting the 'ignorant natives' in case a Bene Gesserit needed protection. Then you have the selective breeding program that Jessica was part of. Complex machinations just to produce the "Kwisatz Haderach" a super computer in human form with an inner eye focused on the future. The planning that went into this is astounding, as the appendix recounts Jessica's gene-markers had been cultivated for 2,000 years. And taboo for us, such close in-breeding, was just waved away by hiding Jessica's parentage. Jessica messed everything up for them though, by having Paul instead of a daughter to join to the Harkonnens and then produce the KH, Paul was just a generation early. Also, their human test is pretty interesting. I suppose they are simply testing the measure of the person by seeing how they stand up to pain, I'm sure there's an adage out there about that. There is about everything else.
Next, the aristocracy and social structure, the Great Houses and Emperor. More complex than England, and they beat out everyone else here on Earth. Then again, they've got planets to stretch across instead of just one island. In Dune, dukes are at the top of the food chain, besides the Emperor, of course, and his children as princesses and princes. Dukes, counts, barons, ladies, and princesses. Oh, noble hierarchy. Houses control planets until they are moved around. The Atreides family controlled Caladan before being moved to Arrakis, a supposed honor. Familial ties to other houses were often worth their weight in gold, or spice I suppose, and marriage played as much of a role in power plays as it has on Earth. Leto couldn't marry Jessica because he had to be kept free in case a deal required marriage with another house. Paul married Irulan for the link to the throne while Chani had to stay a concubine, though she won in the power game with Irulan, in this book at least. And any relation counts, even distaff ones, which I'm guessing are on a maternal rather than paternal line of relation. As the appendix describes, major houses get planets and interplanetary business while minor ones just get planetary business without possibility of branching out like the major houses can (520). Very interesting arrangements, though perhaps less complex in a single family than Heinlein.
Last, let's discuss spice. A drug that helps you see the future and navigate through the universe? Cool! Well, except for the blue eyes thing...could be kind of creepy. And the whole Navigator deal of turning into something other than human. Okay, fine, not so cool. But still interesting. The Guild formed the other piece of the square between the Emperor, Great Houses, and Bene Gesserit. It controlled space travel and transport, as well as the banks. Tick them off and you're stuck on your miserable planet, unable to go anywhere and probably broke too. The universe is dependent on them for travel and they are dependent on a substance found on one planet that is fraught with contention, a radically religious local population, and meddling by the houses. Fun. Oh, and there's these giant worms that make extracting the spice, from sand mind you, very difficult and dangerous. Double fun. You'd think they'd try to synthesize it or something. Or demand to control the planet themselves, the Guild that is. It just doesn't make much sense, putting all of their eggs in one basket like that. Again with the parallels to our own circumstances.
If anyone wants to borrow the movie version of Dune, I've got that too. And it's pretty close to the book, which is unusual. Well, "the spice must flow".