My colleagues and I have published a new study in IJGI:
Biljecki, F., Stoter, J., Ledoux, H., Zlatanova, S., & Çöltekin, A. (2015). Applications of 3D City Models: State of the Art Review. ISPRS International Journal of Geo-Information, 4(4), 2842-2889. doi:10.3390/ijgi4042842
This review paper provides a comprehensive overview of use cases of 3D city models. During the work 29 use cases have been identified and described. The paper is supported by 400 references of related work. The PDF is freely available (Open Access) from the publisher’s website.