I get a feeling we will be able to turn faith into tourism (pilgrimages!) and that religion will be one way to go for in a culture victory (it'll depend on where you lay the focus yourself). In this way, religious city states would become important for cultural victories in the late game which is better than the insignifance* Religious City State become later on. I do agree that straight tourism city states would be bad though.
*if we exclude the exploits of buying Great People..
Agree that the poll is not particularly useful, I'm not sure you can poll that topic at all even.
Some suggestions for City States:
Palmyra (mercantile or militaristic, really want to see this one)
Najaf, Isfahan, Lourdes, Pataliputra (all religious)
Samarkand, Bukhara (mercantile, are they on the Mongol or Persian City Lists?)
Daccar, Lagos, Khartoum, Nairobi, Dar-es-Salam, (whatever's needed

)
Dubai/Abu Dhabi/Muscat (I know, on Arab list, but they would pe prime examples for City States, no?)
Teheran, Karachi, Kabul (militaristic, cultural?)
Vilnius, Kiev, Zagreb, Riga, ... (what would we do if we run out of European city states

)
Cahokia, "native names of mesoamerican city states, not the current spanish name of the excavation site" (looking at you, La Venta!).