New technologies such as 3D integration are becoming a new force that is keeping Moore's law in effect in today's nano era. By adding a third dimension in current 2D circuits, we can greatly increase integration density, reduce interconnection length, and enable heterogeneous systems within one package. In order to exploit the advantages of 3D integration, layout designers and tool developers need to be fully aware of this rapid development. This paper gives an overview of recent 3D integration technologies, such as 3D packages and 3D integrated circuits. We then analyze and compare 3D data structures in order to draw conclusions about their future potential. Finally, the impact of 3D technologies on interconnect prediction is discussed.