By stating "nanotech + stem-cell = near immortality" I only showed the frame of a picture. Imaginatively and theoretically this only "seems" true.

I am very well aware of the major environmental and resource based problems. It is also almost true that human race will be extinguished before the aforementioned accomplishments are done.

I am also aware that these research areas are in their premature periods. But they are promising "near immortality" so why not. The equation can be extended

"near immortality" + people continuing to breed like rabbits + major wars = "Then what good is near immortality"

I say just accomplishing is good. Also this near immortality may make it possible for settlement on external planets or even deep space voyages possible. But if I talk about all of these it will be science fiction.

So they are promising, but we should wait and see. It is good to accomplish something. We can never say a scientific research is useless.