I came back from my vacation in the land-that-is-always-suggested-as-a-civ-but-is-too-small-to-work-well with an idea for a modern religious wonder:
Bahá'í Gardens (Tourism, requires Judaism, Islam and at least another religion in the city) [Ottoman/British/Israel]
No instability from religious disunity
Idea: This would allow representation of the Bahá'í faith, which emphasizes the truth of all religions. It could be another effect related to having multiple religions if this one is undesirable or already in use somewhere I'm not aware.
I'm guessing there's no art for this, and I realize that this will probably spell doom for this suggestion (maybe something could be worked from the oracle model, it looks similar to the
Shrine of the Bab). So at least I'll try to make this post useful by discussing other wonder-related things.
Perhaps the Atomium should give +1 Uranium, +1 Aluminum and +1 Iron. Thus it would be a way for smaller civs to access uranium and aluminum without needing to expand to ahistorical places. Uranium because the wonder represents the Atomic Age, Aluminum because it was originally made out of aluminum, and iron just for fun because it actually represents an iron crystal. Can tweak the number of resources it gives if needed.
Nalanda University was a Buddhist monastery; shouldn't it require Buddhism? (Perhaps in addition to Hinduism to ensure location in India.)
And a question: are there any long-term plans about changing culture and cultural victory? The thing I liked the most about Civ5 that's not in Civ4 is probably the tourism mechanic: the idea that you can use culture offensively to increase your influence over others, and win when you influence everyone. As of now in Civ4/DoC, culture becomes more or less useless in the late game unless you're going for the incredibly boring cultural victory, and thus so are great artists and many wonders and buildings. In Civ5, it was kind of exciting to try to increase your tourism output, or at least make sure your cultural output is strong enough that you don't fall under the cultural influence of others. I realize this is off-topic, but if something like this ends up implemented, it would give many more possibilities for wonder and project effects in the late game.