I’m using recent release of Cesium - build 25, and seems to me that inertiaZoom property doesn’ affect camera’s behavior (as it’s always equal to 0) when I try to zoom in or out (e.g. by scrolling a wheel of mouse). However, in my previous project using build 19 it works. I see the problem with Cesium Viewer demo:
Tested in Google Chrome and Mozilla Firefox on Ubuntu 12.04 LTS.
I’m not sure whether it’s really a bug but I can post it to github.