I'm not directly involved in tech/hardware and I'm imagining full on reality-quality 'virtual reality' beamed into people's brains within 20 years. I imagine those in VR would scoff at this, but I'm kinda hoping I'll be closer to the truth ;-)
Bill Gates has an interesting quote about this phenomenon, for which I forgot the exact wording... it says that you are always wrong as to how fast things will occur, but you are also wrong when you think stuff will not be available for a very long time. There's many examples of such assumptions being wrong now and then.
KnightLore 1984 http://retrospec.sgn.net/users/ignacio/images/knightlr.gif
Did you never go to a video games arcade?
BattleZone came out in 1980
Seriously, the PC took years to become State of the Art when VESA local bus freed us from IBM dictating the game with E/ISA and ceeding control by trying to force MCA on the world.
Anyone who knew about Trocadero http://en.m.wikipedia.org/wiki/London_Trocadero knew what was coming
There was a Transputer network game doing realtime raytracing!
Wasn't Moore's law[1] as widespread as it is nowadays back then?
Since I was at Intel at the time neither one of us expected computers to get 1,000x better than they were at that moment in time (the 80286 @ 10Mhz woo hoo!) I was driving a BARCO 1024 x 768 RGB monitor that cost Intel $3,000 to purchase, they were predicting it would be under $1,000 in the next 10 years or so. Its hard to have little animated pieces running around recognizably on a pixel budget of 15 x 15 and perhaps 8 bits per to select out of a color pallet of 4096.
So the photo realistic stuff we saw at Siggraph we didn't expect would be 'real time' in our lifetimes, certainly not at anything close to affordable a price. And yes, we were way off base, but that is the nature of things.