As a follow on to the recent post about future filters civilization may have to survive, the Technium provides this post that considers possible transitions civilization may go through in the foreseeable future:
Next Transitions in the Technium
"What kinds of developmental thresholds would any planet of sentient beings pass through? The creation of writing would be a huge one. The unleashing of cheap non-biological energy is another. The invention of the scientific method is a giant leap. And the fine control of energy (as in electricity) for long-distant communications is significant as well, enabling all kinds of other achievements. Our civilization has passed through all these stages; what are some future transitions we can expect -- no matter the fashions and fads of the day? What are the emergent thresholds of information and energy organization that our civilization can look forward to? Most of these thresholds are gradual, so we can't assign dates, but each of these structures seem to be a natural transition that any civilization must reach sooner or later."