It's quite useful for system administrators or to do a quick hardware check.
Quick overview about the Software and Hardware.
Screen setup and resolution infos.
Storage overview. Seems it has problems with the disc encryption since the 150gb drive is the actually Lion harddrive.
Memory info including physical setup.
Extended Batterie informations, as you see mine needs to be checked.
Support links to manuals.
And finally warranty and service checks (including AppleCare)