The quest for
immortality isn't new. It's a staple of many ancient legends which span across cultures and geography.
The search for
happiness is also not new. History proves it and we, ourselves, are living proof of this.
The two, immortality and happiness, are married together in religion.
It appears to me that the combination of the two, as seen in religion, necessarily implies that one is not the guarantee of the other - we could be immortals in hell and we can be happy mortals. This relationship is quite symmetric - happiness is devalued by death and immortality is devalued by suffering. The two are tied together to be of any worth, as far as we're concerned.
As the OP states immortality seems to be within reach of modern medicine and technology. I don't know when and how BUT I'm quite optimistic in this regard because we do have very long-lived species and to me, perhaps in very simple terms, all we need to do is unravel the secret of longevity, adapt it to humans and implement the remedy. In a nutshell, we're not simply daydreaming on the subject of life-extension.
Happiness, however, is not so easily dealt with. It's a complex emotion and 2 thousand years of thought by the best minds humanity has to offer hasn't yielded definitive answers. People are deeply divided on the meaning of happiness.
Perhaps it's a mirage and there is no such thing as a universally meanigful definition of happiness and we're free, individually, to find and live in our own private versions of happiness. If this is the case then immortality seems even more attractive as we're relieved of the burden of trying to find happiness and we may live our eternal existence in our own terms - doing what give us joy.
So, I do find the prospect of immortality very attractive. People wouldn't be lamenting ''so much to do and so little time'' and great minds will have the chance to maximize their potential - imagine if Enistein, Aristotle, etc. were still alive.
That said I think immortality, if realized, will have broad and deep impact on every facet of civilization.