Maybe I'm not using my imagination, but I can't imagine why you would ever want to rotate a pivot point...they are just for the object to refer to when doing transformations...what is it you are trying to do? Do you want to be able to move it along an axis that is not aligned with the world axis (local movement) so it's easier to move on a certain angle?
Also, please don't be offended by this, but are you new to Maya or 3D? If so, then the part about "not needing to" should apply. If you aren't new to 3D or Maya, please elaborate on what it is you are trying to accomplish by doing this.