Robots like Star Wars would be easy, we just havent mass produced annoying bleeping Mars Rovers yet. Or given clunky bad-at-walking robots annoying or snarky voices yet. It's not exactly impossible with current technology to have something respond to you with a snarky voice, ever seen one of those voice command phone thingies that acknowledge you in a sexy female voice? We just need to replace the voice with something that sucks and we're at Star Wars.
I guess the thing with hovercraft is that we have had the technology for ages but wheels are just easier, more efficient and break less. Flying cars dont seem to make much sense, imagine how you'd need to do roads and traffic lights in a city, or air control, not worth the effort. To perfect or refine a technology, there needs to be a demand for it. What seemed like super advanced sci fi in the 70s/80s is largely possible now, we've either already got it or there wasnt any demand for it.
Ummm... Not exactly what I meant...
Its easy to create cool sounding machines that are like a parrot. They just say the same thing over and over like they're a broken program. Thats what most AI today are. Being able to create good "droids" like we see in movies is impossible. They will never be able to process and respond to so much stimuli like a human can.
The human brain is like 1000 supercomputers running at once, and no technology we ever make will match its problem solving, intelligence, or ability to interact and respond to changing situations.
