Mabey I am just to religious, but I do not think that God will ever let that happen. Remember, man used to live to be a thousand in the time when God created man. I believe Adam died at 932 years old or something around that. Then the time of man's life was reduced to 120 years.
I definatly think God created us with the ability to engineer ourselves to live longer. We were made in his likeness.
The last time man did something on this scale, it was called the Tower of Babal. And God changes the languages they spoke so that none could understand one another. We have since then overcome that day with the creation of instant translators and the net. I am curious to see how far God will let us go again.
Plus, leaving on earth is hell as it is. I would rather do my 70 as God promised and get done with it.
edit: plus with great wisdom, like leaving 1000 years, demands great responsobility. People would not be resposibly enough to not overpopulate the earth as many have already mentioned. But space travel could fix that problem. I might be willing to leave a 1000 year if I can start my race of people on mars. A true Martian, that would rule.