Would you like to live to be 1000? Should everyone have the right?
http://news.bbc.co.uk/1/hi/uk/4003063.stmThe length of life will be much more variable than now, when most people die at a narrow range of ages (65 to 90 or so), because people won't be getting frailer as time passes.
The average age will be in the region of a few thousand years. These numbers are guesses, of course, but they're guided by the rate at which the young die these days.
If you are a reasonably risk-aware teenager today in an affluent, non-violent neighbourhood, you have a risk of dying in the next year of well under one in 1,000, which means that if you stayed that way forever you would have a 50/50 chance of living to over 1,000.
And remember, none of that time would be lived in frailty and debility and dependence - you would be youthful, both physically and mentally, right up to the day you mis-time the speed of that oncoming lorry.