Exactly - the body is just a shell. Keeping it alive artificially past its normal span would just be stupid. If dietary changes can slow the aging process, however, that might be good - aside from bankrupting Social Security and Medicare even faster. ;)
And as the Eastern religions make clear to us (and the early Christians also believed, before the Church decided the fear of death was more profitable), your soul can always choose to incarnate again - you could live two vibrant 75-year lives within that same period instead of spending the last 75 years of a 150-year life as a worn out relic.
As far as the Ray Kurzweil idea of transferring one's consciousness into a machine, I don't believe that will ever work. We might learn how to copy memories from a brain like downloading data to a disk drive, but the soul is multidimensional and can't be bound to a piece of machinery. At best you would end up with a robot full of memories - but the soul that made you an individual will be somewhere else, waiting for a chance to incarnate as a human again.