James Hughes, in a column at Betterhumans, floats an interesting semi-objection to radical life extension - that turns out to be more of a side journey into asking what it means to be you. Plausible future technologies will make this an increasingly difficult question to answer, but philosophical speculation certainly doesn't invalidate the fight against aging! In any case, Hughes returns halfway to the fold by the end of the article, concluding: "So bring on radical life extension. It will make us all happier, better people, and we will live long enough to honestly not fear death, partly because we will know that everything we are will continue on in some form."
Link: http://www.betterhumans.com/Features/Columns/Change_Surfing/column.aspx?articleID=2004-04-21-1