October 21 2015 was the future date that the heroes of Back to the Future II (1989) travelled to. The film, like Back to the Future (1985) and, to some extent, Back to the Future III (1990), was a massive box office success and a popular culture landmark. It is getting renewed attention at the moment as people speculate on just how accurate this film’s ‘predictions’ about the future would be (for example, see the BBC for a report).
Overall, there are quite a few things that have either arrived or are imminent in some shape or form. Even hoverboards have been demonstrated in a limited way, although relying on metal surfaces to levitate; the other day, I saw a video of what looked like four or so flying drones hooked together to form a flying platform that could carry a person. Some of this is of course driven by people who saw the movies when they were kids and have spend their careers trying to recreate the ideas that struck them; time travel (or certainly science fiction) demonstrably changing our future!
There were of course plenty of misses too. For example, the fax machine has almost died out instead of becoming one of the global communications media of choice while smartphones are conspicuously absent. I suspect the day will pass with no-one spotting a genuine, fusion-powered Delorean, although I also suspect an above average number of look alikes will be driving around! Meanwhile, we will have to be content to travel into the future one day at a time.