What we know: The Civ2 wonders will be kept but some will have different effects. New ones will also be added.
The Great Wall will, instead of the old benefit, be a physical part of the map over which enemy attacks will be more difficult. The Great Canal is a new wonder which you can use to link two oceans with a passable canal. Another new wonder is The Internet, although they had not at the time of that article figured out what exactly it would be for.
Minor wonders that can be built by every civilization include the SDI defense and the Manhattan project.