In The Postmortal, the cure for aging is invented, and Drew Magary takes a stand at where he thinks the world will go in a different society where nobody dies of old age. It's interesting to see every day society transform so suddenly without the use of a ludicrous apocalypse. He brings up quite a few interesting ideas in such a setting, and a lot of these have merit. I won't spoil anything, though.
First things first, I'll say that immortality isn't as far in the future as you probably think it is. Of course, you probably hear that a lot about flying cars that run solely on water and stuff like that, but there are reasons that sort of technology doesn't have the spotlight (though in some aspects it already exists). If we got as many people to research a cure for aging as we have researching cures for cancer or some disorders, I'd hazard to guess we would probably find it within thirty years. And I don't know if there's a real reason our society isn't seriously looking into the idea, but it's a real possibility.
I wrote an essay (for the same class, obviously) about what the world should do in the case that death was almost nonexistent. I personally believe that if people had the choice to freeze their age at the prime of their physical life (say, twenty-five) our society could seriously improve. Just think if all of the greatest minds of the last two centuries alone were able to get together and work towards improving the world indefinitely. If we didn't have any elderly to take care of, because all of those would-be aged people would still be in the work force and be in full charge of their lives.
So much would be different I think it would be safe to assume we have literally no chance of accurately predicting what society would be like if immortality was an option. Certainly, it would be nothing like our own, as we live our day to day lives knowing our time is limited. If there was no definite limitation on how long one could live, how would everybody go about making a livelihood?
I'm no statistician or anything like that, so I would be the last person anyone could expect to make any accurate predictions on what would happen. I just thought it was an interesting question. Drew Magary's perspective on the things he brings up is pretty thought provoking, too.
Overall it's an odd book because it's not really character driven, yet it's told in first person. I'm not sure I agree with that aspect, but what do I know? I'm not an established author. So if you're looking for an interesting stand alone philosophy and sci/fi book, I'd recommend this one. I could also recommend Orson Scott Card's Ender series, though I've only read Ender's Game and Ender's Shadow, the part of the series that has very little actual philosophy in it. But a famous author has got to have achieved his merits, so those books must be good.