No, definately not small changes. But there will be no changes to game play (new civs, units, etc) other than the AI being smarter, and possibly a few minor flavor changes (reduce the spread rate of RoK or FoL etc, change the AI weight for grabbing religions). Do note however - the AI WILL be much more competitive with these changes, doing things like actually getting an economy before beelining bronzeworking, etc. If you want an example of how it will work, go grab Wild Mana 5.0 lite, and don't select any of his new options in a custom game. This may not be exactly how it will come out, but it will be a very close approximation.
-Colin