Here is a list of the more popular governors, but some are not on the list
Android CPU governors explained - Android Forums
From reading the list it only mentions that hotplug can turn off a processor on dual core systems. However, just because it doesn't mention this ability on the other governors does not necessarily mean the other governors cannot do it, so it would be useful if someone can confirm this ability on the other governors.
I noticed better battery life when I switched from ondemand to hotplug probably because hotplug can turn off the second processor when it's not needed.