Its not at all a problem that there are more than one thread on this subject, this actually deserves a lot many.
I think even though we have made a lot of progress in every field, three main and necessary ingredients are still missing from the scene. These are
needed for singularity to happen.
1) A new, unlimited, clean and abundant source of energy
2) Artificial general intelligence
3) Nano manufacturing.
We are still using fire and waterwheels as our sources of energy. (electricity is only a convenient form of it, we still need to burn something or
erect dams to get it). To match the near infinite speed of progress thats expected during the singularity days, we need a near infinite source of
energy because surely its not possible to do anything without energy. The whole earth's bio-fuels etc will be consumed in a matter of days, if it
really starts to get closer to singularity and you know everything will suddenly come to a screeching halt.
We can build dams etc, but it takes years and years and surely they are also limited, because they are dependent on amount of water in the rivers and
so on weather.
So I don't see singularity happening without a new energy source. (And its difficult when people in power are actively preventing its development)
Second, with all the huge progress being made in IT and communications, we are getting things done faster and faster. It all sounds very promising and
is really promising but there is a catch. The ultimate source of information and knowledge is human, thats us. So the progress in knowledge is limited
by what a human mind can do. We have synergies of a million minds working together and exchanging information at an ever growing rate, but not enough
for a singularity to take place. An average human spends most of his time in 'lower level' jobs of maintaining, sustaining and protecting
himself.
Once we have an artificial intelligence which is capable of doing what a human does, we will be liberated from most of the 'lower' level work and
can concentrate solely on creation. Moreover a self improving AI (or AGI actually) can overtake human intelligence level and bring on the singularity
much earlier.
I'm most hopeful in this area. This is surely going to happen within our lifetimes.
Third, even with unlimited energy and unlimited intelligence, you need stuff to create things. Our current method is to painfully dig it out from
earth and purify it and then there is long process that goes in designing, manufacturing, assembling and maintaining it etc. This must change, else
the singularity will remain only on papers.
Nanotech is the answer. It means, we will be able to produce anything instantly (or fast) on the spot by using the basic building blocks (atoms). This
is our dream of universal fabricator and we have already taken steps towards it. This will of course mean collapse of current economical and political
systems, but then nothing will survive singularity.
I wish I could provide links to all the buzz words mentioned here. But the interested reader can find everything on Google. You'll be hooked forever
to this stuff, its so interesting.