20 years is a long time. My bet is that all the colors will fade away, as priorities like survival as a race will come first.
This is by no means a pessimistic view, as the exponential growth of data won't slow down much. Just for most of us
- the access to it will be via 70s style ascii terminals rather then holodecks.
Think flying cars in the 60s. And then think middle east now.
However, the technoloy race will continue in the background (with a less focus on making white devices with huge powerdraining screens and more focus on smaller processors) - making the web a suitable host for those who will aford digital versions of themselfes, agents to take care of all digital needs.
The web in 20 years? Will be the only wonder of the world still standing :)
[later edit, +Hendrik Sijswerda
convinced me this topic deserves some optimistic view :P ] so here it goes:
20 years go by, we manage somehow to keep the consuming status quo. Don't ask me how I have no clue :)
The web will grow in dimensions, getting all our needs inside, not only communication and information. Each an every object in the physical world will have a digital synonym in the so called 3d web (think Opensim and it's hypergrid protocol), and technologies like AR and ubiquitous computing will blend reality into a powermix of digital and virtual. We'll get better at real world by filling it up with digital possibilities and probabilities, through gamification.
In this scenario, I think before 20 years we'll use DNA to sign our digital fingerprints, as the ultimate privacy mechanism.
20 years is a very long time. 20 years is the new 100 years.