I think biggest change in next 20 years is obviously increased internet bandwidth- and the "disappearance" of the internet because it's taken for granted. Monitors will disappear and be considered a strange part of Early 21st Century. Montiors will be replaced with "sunglasses" and surfaces in which images are reflect from (like projection TV)- the images could projected on any surface, but for higher resolution there will special "screens". Computers that we would be more familar with will be become a part of "camping gear" -like gas cooking stove.
In other words your environment will be synthetic- visually, sonically, and other senses- the real world will overlayed with "enhancements". And Terrorism will be outdated, an unique problem of an unmodern world.
Maybe that's too optimistic, it may be just beginning in 20 years, it might take 30 years. But this "phase" will even be shorter than next phase which the internet and computers are completely undetectable and you get a "enhanced" human "wired" into different world than "unenhanced" humans.
Of course before this, something will have done about computer viruses and other net attacks- if this is unsolvable, war will be this form.