Similar to the recently implemented option to have layer groups act as a mutually exclusive radio list, the idea here is to allow the label classes of a layer act in the same way. This would be useful in a scenario where you have configured fitting strategies for different scales, map themes, what have you. Sometimes it's useful just to be able to flip around as you go about your own work, or are showing someone something interactively. Right now it's a bit of a pain to fumble through these settings no matter where you do it; the TOC is probably easiest but still an extra click every time. I envision this similar to the layer group - R click the layer name and select the label class type.
