Can I just copy "Z location" to all the selected objects? "Copy to selected" copies the complete location X, Y and Z to all the selected objects. I wish to copy only Z location. Please see the images bellow to get idea of what I intend to achieve.

Before


After
You can also try another way:


Switch pivot point type to Active Element, toggle Manipulate Center Points;
Select objects, keep one active, then SZ0.




UPDATE:

Thanks to Bastien Montagne (aka mont29)'s commit, you can find this feature in latest version, now only for Location, but also Rotation, Scale, Dimensions, etc: