Singularity is the moment when a computer will be aware of itself and so a self-conscious being, not exactly the uploading of a human brain to a computer.
It won't make us immortal for two reasons:
1) It won't be us, but a digital clone of us. We will still die.
2) Soon or later something would happen to the computer. It would be destroyed by a war, a catastrophic event, the end of our sun, the end of our universe, etc. Death would wait for his destruction almost an eternity if necessary, but it would happen. As physicians say, in nature, if something is possible, it will be a necessary event, because it will be just a question of waiting enough time for it to happen (see
https://bitcointalk.org/index.php?topic=1221052.0).
Since there can't be any immortality, and death is our destiny, unfortunately, the issue of the effect of immortality on the value of time can't be really tested. Clearly, being able to live thousand of years would lower the value of our time. But I surely wouldn't mind to have time to be able to real waste it.
In the end, the only positive way to part from this life would be if we were completely bored with it. Think about it: life is like a relationship, the only happy way to end it is if we were tired of it. If we still love it, death will always be a tragedy.
Beside, being able to make our own decision to end life is also a positive thing. Death wouldn't be imposed by nature, but would be our own decision. One of the major problems of death is that is imposed on us against our will.
Of course, parting this life because of are bored with it wouldn't be exactly a happy moment. But it might be less unhappy than to parting it when we are still in love with life.
I'm not making an apology of suicide. In our current conditions, where life is a blink of an eye of awareness, in between two eternities of being nothing (before being alive and after being dead), suicide seems absurd. Even if life was a pain (not literally; if it was really a pain, euthanasia would make completely sense), why rush things?, we'll be dead "soon". But if we could live thousands of years, suicide could make more sense.