Just arrived
My copy just arrived this morning. Yes, it has the content from Play the World as well as all-new material.
The new Wonders are interesting - the Statue of Zeus generates a free Ancient Cavalry unit every 5 turns, and it can later become a tourist attraction (1,000 years after creation) which increases trade in that city. That means a Wonder can be effective for a while, become obsolete, and then become a trade benefit later.
There are also new techs in the tree, allowing boats earlier.
Some diplomatic options (Trading Communications and Trading World Maps) require specific technological advances (Writing and Map Making) before they can be used.
Some new units can now enslave defeated enemy units, making workers out of them. Scientific leaders can appear; and more city specialists are available (in addition to entertainers, tax collectors, and scientists, there are now policemen).
Communist nations can build a Secret Police Headquarters, acting like a second Forbidden Palace.
Additional special terrain bonuses (tobacco, bananas, and more) appear.
Wetlands are a new terrain type. They can be drained when the right tech is researched.
All-in-all, it looks good.
