Couple points : When singularity will be reached, we will not know about it. We will only know when it is approaching. Mainly because "we", traditional biological human beings, will cease to exist, as we know us. So as the world, the reality, will cease to exist as we know it.
The entities such as time, distance will lose their meaning and will disappear. The moment will last an eternity.
The disciplines currently pushing the border of singularity are: nanothechnology and genetic engineering.
Nanotech will yield shortly phenomena as general INVISIBILITY, because light can be bent and/or trapped, and subatomic, subquantum computers, whereas processors, computers, intelligence will become an intrinsic, natural part of a matter. So a brick of the near future will be smarter than a tire of yesterday:], and smarter than the collection of all supercomputers on earth today. Incredible magnitudes of change.
Genetic engineering will yield shorty an IMMORTALITY of human beings, via organs growing, harvesting, transplanting, via aging process manipulation.
Is all this progress and completion of singularity inevitable? No, it is NOT. It is a completely random process.
Tomorrow, any cataclysmic even on earth, natural or mankind made, may destroy most of life on our planet, pushing us back into caves.
We must realize we humans are programs, processes running inside a brain. An incredibly sophisticated processing unit, vastly unmatched by todays computers.
If today you read about flies, insects, being flown, animals being controlled remotely via electrodes in their brains, it is because it is an old news, and the secret laboratories reached some much more advanced levels, pushing the boundaries of imagineable.
Further I think it can be said that singularity will be about to be reached when its imminent permanent inevitability will be assured.
Meaning, we must code ourselves into stone, our whole genetic information, so that human beings can be restarted according to saved blueprint. Code ourselves into vapors in the atmosphere and in the Universe, should something happen with planet earth.
We must reach, enter, inject our building recreation code information into atoms of helium on the Sun, so that our information will live on and in the sun.
When earth and sun both explode, we need human building genetic code to be stored elsewhere in the universe.
Then, and only THEN, the singularity will have been achieved.