I have know google to release stand alone software for the corporate landscape. I pointed out google earth, I could have also mentioned their search utilities..
http://www.google.com/enterprise/
But you're right weather or not this will be offered as a stand alone server is anyones SWAG at this moment. I just think it would float like a lead balloon *unless* there was a standalone, and the guys in google business department are no less savvy than the guys at Microsoft..