Google has now unequivocally stated that "public" means "public," and hence users of Google Apps need not worry, as CNET reports. The problem, as ever, is that the term is still not defined properly, whatever Google's good intentions (and I genuinely believe that they are good).
This is super easily solved by Google:
David Vaile, executive director at the Cyberspace Law and Policy Centre at the University of New South Wales, Australia, said Google should give a clear and explicit definition of what is "public," and also offer an interface that lets users control the attribute on a page-by-page basis and reminds them of this status.
Highlighting potential for the term "public" to be contested, Vaile said it can be construed in different ways, depending on the legal context. For example, in a defamation case, for it to be deemed "public," only one other person needs to hear of it or become aware of it. "It doesn't necessarily need to be in a public place, but it is beyond you and the subject you were referring to."
However, Vaile said Google should be credited for its attempt to set out the terms and conditions in plain English.
As do I. The stakes are high enough here, however, that I think Google needs to define public (or do these technical measures that are suggested above) and be done with it. It's not a trivial issue.