Well, computers were anticipated in 1671, and

The origins of the Internet reach back to research of the 1960s, commissioned by the United States government in collaboration with private commercial interests to build robust, fault-tolerant, and distributed computer networks. The funding of a new U.S. backbone by the National Science Foundation in the 1980s, as well as private funding for other commercial backbones, led to worldwide participation in the development of new networking technologies, and the merger of many networks. The commercialization of what was by the 1990s an international network resulted in its popularization and incorporation into virtually every aspect of modern human life.

The term "cyberspace" itself was coined by William Gibson in his 1982 short story "Burning Chrome", though it is indelibly associated with his later novel Neuromancer (quoted above). The setting in this story involves computer networks whose operating system is now a virtual reality simulation of a TRON-like "world in the computer".

Jules Verne didn't anticipate Submarines: there were already quite a few of those back then although none as huge and NERV-Titanic (relative to the era) as the Nautilus.

But, IMHO, the ultimate example is:

Snow Crash is basically the tale of a sword-slinging hacker who teams up with a badass Kourier in a Post Cyber Punk disincorporated USA to fight "Snow Crash" - a computer virus for the brain. Oh, and there's a badass biker with glass knives and a nuclear bomb strapped to his motorbike, too.[...]The book is also notable for its uncanny prediction of future internet trends. While holographic web terminals have not yet come to pass, we do have heavily populated 3D virtual worlds, satellite photograph software, and a massive user-created online library. (Actually, Second Life and Google Earth were inspired by this book.)

So, the ultimate badass achievement for science-fiction writers isn't to just anticipate stuff, it's to have their anticipation cause the changes and inventions in the first place, as a self-fulfilling prophecy.

So, no, I'm not too worried about making stuff up, cuz that stuff might actually end up being made when it otherwise wouldn't be. We're free-roaming in Idea Space, man, let's just enjoy the ride and try to come up with something fun as well as pedagogic. Plus, the fun thing about Less Wrong is that our focus on human biases and systematic errors gives us foot to write plots that aren't all that sensitive to Zeerust, relying on deeply-seated human idiosyncrasies instead. Going that route is also the easiest way to appeal to the mainstream and to get the high-status "Literature" qualifier, which is always good publicity AND it would allow us to slip our Author Tract in a fairly honest and straightforward way without making it a heavy handed filibuster...