I simply assumed that "inset faces" was intended for either a single face or a group of faces and "inset polygon"  was intended for a single face only.  They have different effects and the "I" key does the same as the "inset faces" tool.  As I see it, it is working as intended - could be wrong,though, I'm very much a novice with Blender :)

Well, the hotkey is working as intended, however if you invoke the operation using the Toolshelf button on a group of faces, it creates extra edges which are certainly not intended as part of the inset process.  As Maxxxmodelz showed in the examples he posted, these extra edges cause topology problems, and make the operation useless on groups of polygons, if you use it from the Toolshelf button.  Most people use the hotkey "I" , so it doesn't matter much, unless you're new to the software; in which case, someone might mistakenly assume the entire feature is broken.

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