I'd like to see bridges, or re-claiming land. I once played as France, building some continent-only wonders, only to discover that the map was not a Pangea, like I had selected, but continents (I really hated it when it did that, and it wasn't the first time either)! And worse, it was detached from the large central continent by only one measley little sea square! By the time I had built Galleys and put Settlers onto the new land, the English had claimed most of it, leaving me two small coastal cities with no way of expanding further because the English were blocking the way (I eventually went to war with them, and it was a huge hassle getting troops across, because of having to bridge the gap with ships). I didn't finish the game (intended for a conquest victory) because of the setbacks I had early on.
I appreciate many would find bridges and land re-claiming unrealistic, but I don't see why underground tunnels couldn't be used. And I really would like to have them treat two joined land-masses as one. Wonders aren't only for culture, and some of them have some pretty useful effects but only limited to the one land-mass (e.g Pyramids).
