»Previous versions of the matrix«

I know it's explained that the first version of the matrix was supposed paradise for humans and it failed, and the present one is set in our present day, but are we ever told what the missing five incarnations were like? My point is if they were the same as the present one then there aren't any clues to be had, but if they were different (such as being set in different times in human history as hinted by in the animatrix episode 'Program') then maybe there are some clues to how this trilogy is going to end up; a 7th matrix age in a future setting? I think it would be pretty interesting to see the matrix senario in other setting of history, what with the 'vampires' and 'ghost's' of the older versions...

The Matrix we know know is The Matrix that has existed always (since they found the way for humans to assimilate it). It has never been staged in a different "era". You may picked this up by The Animatrix short story "Program", because the weird outfits and all, but they weren't in The Matrix, the were inside a training program. Otherwise, the so called "traitor" would have died in the real world. The purpose of the program was to test people in order to see if they had a tendency to be traitors (like Cypher).

Agent Smith: Have you ever stood and stared at it, marveled at it's beauty, it's genius? Billions of people just living out their lives, oblivious. Did you know that the first Matrix was designed to be a perfect human world. Where none suffered. Where everyone would be happy. It was a disaster. No one would accept the program. Entire crops were lost. Some believed that we lacked the programming language to describe your perfect world. But I believe that as a species, human beings define their reality through misery and suffering. The perfect world would dream that your primitive cerebrum kept trying to wake up from. Which is why the Matrix was redesigned to this, the peak of your civilization. I say your civilization because as soon as we started thinking for you it really became our civilization which is of course what this is all about. Evolution, Morpheus, evolution, like the dinosaur. Look out that window. You had your time. The future is our world, Morpheus. The future is our time.

If they created a new version of The Matrix, set in a different era, they would have a big problem making the humans plugged in assimilating it.