So far, the ButtonGroup widget offers purely display capabilities.
It looks beautiful, much better than jQuery's Controlgroup widget.
It could be an excellent complement to other Kendo widgets like the DropDownList widget.
Ideally, it would accept a map with value-label pairs just like a DropDownList for display and accept and return an array of selected values.
That way it could often replace radio button or checkbox groups which - in my humble view - lag behind in terms of modern appearance.