Bad idea unless we get major space colonies going.
Might not be able to save the Earth from overcrowding, but there will be hope out there.
Believe me, the first people who get the immortality treatment, unless it's almost free, will be exactly the people you don't want to live forever.
Cultural evolution will slow, and pretty much stop. Children are a fresh start in more ways than one. Quality of the film aside, one of the more realistic treatments of how immortality would affect a society was "Zardoz."
Before we have immortality, we damn well better have some exploration space.