Town
Everyday buildings on mini fig scale, e.g railway stations, businesses to fit train displays Yes, this is definitly what is missing, but another train station would be a letdown. What about houses ? Think, houses... mhm, those stuff people are living in...
Bridges Yes
World Buildings
Taj Mahal No
Sydney opera house No
Empire state building No
To me, it is almost impossible to do those buildings with a good level of details at an affordable price. I can't see die hard Sydney opera house fans anywhere that would be ready to spend 369 euros on a set (unlike SW fans)
Vehicules
Muscle cars, hot rods No, too many of them already
Ferrari e.g F40, F50, specific historical race represented No, too specific
Classic cars No
Aircraft
Civil transport planes Yes, if they are different from those we already have (the two available world city sets containing airplanes. Smaller or bigger planes with different kind of engines would be cool
Classic planes from the early days of aviation Yes !
Other Structures
Oil rig with functions Depending on the functions, and more importantly, it has to be MF scale
Amusement park with functioning mechanical rides definitly a great idea !