http://www.hedweb.com/hedethic/hedonist.htm

This is a link to a Hedonistic Manifesto. It's pretty interesting reading. Here's an excerpt from the introduction:

This manifesto combines far-fetched utopian advocacy with cold-headed scientific prediction. The Hedonistic Imperative outlines how nanotechnology and genetic engineering will eliminate aversive experience from the living world. Over the next thousand years or so, the biological substrates of suffering will be eradicated completely. "Physical" and "mental" pain alike are destined to disappear into evolutionary history. The biochemistry of everyday discontents will be genetically phased out too. Malaise will be replaced by the biochemistry of bliss. Matter and energy will be sculpted into life-loving super-beings animated by gradients of well-being. The states of mind of our descendants are likely to be incomprehensibly diverse by comparison with today. Yet all will share at least one common feature: a sublime and all-pervasive happiness.
This feeling of absolute well-being will surpass anything contemporary human neurochemistry can imagine, let alone sustain. The story gets better. Post-human states of magical joy will be biologically refined, multiplied and intensified indefinitely. Notions of what now passes for tolerably good mental health are likely to be superseded. They will be written off as mood-congruent pathologies of the primordial Darwinian psyche. Such ugly thoughts and feelings will be diagnosed as typical of the tragic lives of emotional primitives from the previous era. In time, the deliberate re-creation of today's state-spectrum of normal waking and dreaming consciousness may be outlawed as cruel and immoral.

Such speculations may currently sound fantastical. Yet the ideas behind this manifesto may one day be regarded as intellectually trite - albeit today morally urgent. For as the genetic revolution in reproductive medicine unfolds, what might once have been the stuff of millennialist fantasy is set to become a scientifically feasible research program. Its adoption or rejection will become, ultimately, a social policy issue. Passively or actively, we will have to choose just how much unpleasantness we wish to create or conserve - if any - in eras to come.