I like to use food to describe the relations under capitalism because there is more then enough food to feed everyone healthy diets (UN FAO claims about twice as much as needed is produced every year) but yet the number of people starving continues to climb. The same is pretty much true across the board: rising inequality means some have none while others have too much. The only way to justify the situation is to claim that the reduced ability to meet needs is due to an absolute lack rather than by hoarding at the top.
It is also true that what we need is socially produced and under capitalism those needs must continually grow.
Also at some point, maybe now, capitalism will cease to be a revolutionary force and become a hindrance to production (too orthodox?). This is tied in with the individualization of society because we produce and innovate best as social animals. If we continue to remove that social character we will remove what made humans unique (that we are the most social of all animals due to our complex language development which allowed us to pass on knowledge). So it isn't just that capitalism will cease to be revolutionary in strict production terms but it is de-socializing us and this will hinder our capacity to develop.
Brad