There's been a fair amount of talk bandied about about post scarcity economies (see Cory Doctorow-Down and Out in the Magic Kingdom). Now, I would hold that there is no such thing. The conventional definition of a post-scarcity economy is more artifacts and information than an individual can consume in a given period of time, but in actuality, this kind of scarcity is mediated by expectations of what should be consumed. Modern society exists in a post-scarcity economy by any historic definition. In the first world, even a moderate income provides levels of food, shelter, and entertainment higher than those enjoyed by historic nobility.
What remains scarce are luxury goods, expertise, and finally attention. Luxury goods are not an absolute, they're relative to the productive level of the culture, the shifting status of meat is one good example. Even in a universe of home nanoreplicators, there will be some objects not amenable to nanofabrication for technical reasons, or 'handmade' items will have cachet for status reasons. Expertise covers any form of service requiring intelligence or skill, anything from legal advice to a massage. Even in a world where artificial intelligence makes modern expertise cheap, there will be some computationally intensive projects that cannot be run trivially. . I am reminded of the scene in Zardoz where friend requests an analysis of design trends in automobiles, and refused because the otherwise all-powerful Tabernacle can't spare the processing cycles. As with the claims of “power too cheap to meter” from the early atomic age, intelligence too cheap to measure is another lie.
There is one commodity that can never be made abundant through technological means: human attention. Human beings crave the attention and approval of others. The amount of attention in the world is limited by the number of hours of wakefulness. Even when every material desire has been satiated, we will still desire friendship, and even celebrity, and these goods cannot be faked. What is called the novelty or information economy could be more accurately described as the attention economy. Once energy and physical objects become passe, all we'll have is the ability to pay attention to each other (note the structure of this traditional phrase).
Our economy is transforming into one of youtube celebrities, reality TV stars, and blogger-gurus. Those who can adapt their production to garner attention, and know how to translate it into something more lasting (influence?), will be the movers and shakers of the future.