Of course people are already living longer, which has had impacts on everything from housing to employment. Pew cites the U.S. Census as saying every six years the average U.S. life span rises by a year. However most of the advancements in average life span have been because of a decrease in the mortality of infants and small children.
Respondents to the poll worry about how longer life spans would drain natural resources and harm the economy. The Pew report included an essay based on interviews with bioethicists called "To Count Our Days: The Scientific and Ethical Dimensions of Radical Life Extension." The report said dramatically expanded life spans "would raise a host of new social, political, economic, environmental, moral and other questions," including on concepts of marriage, parenting and the gap between rich and poor.
It quotes a range of religious leaders on the concept of trying to expand life span indefinitely.
Among them were Pope Benedict, who in 2010 warned against postponing death: "Humanity would become extraordinarily old, [and] there would be no more room for youth. Capacity for innovation would die, and endless life would be no paradise."
The Rev. Alistair So, chair of the Episcopal Church's Executive Council Committee on Science, Technology and Faith, told Pew there is nothing in the denomination's teaching against life extension, so long as it doesn't become "the focus of life" and that benefits were available for all.
Pew also quotes Abdulaziz Sachedina, chair of Islamic studies at George Mason University and the author of "Islamic Biomedical Ethics" as saying that striving for immortality would go against Islamic teachings because it would keep Muslims from heaven. "There is a deep-seated belief that death is a blessing," Sachedina says. "We look forward to dying."