In case there was any ambiguity about whether Google knew the 'real you' from their logging of IPs and search terms, this should remove all of it. In a way I think we're seeing Google striking against Facebook in what I call the "identity wars" where each service is struggling to be an identity and information service about people.
How? I mean, obviously, if you use this service (either as a sender or receiver) Google will know more about your real identity as part of conducting the transaction, but how does this say anything about what Google knows "from their logging of IPs and search terms"?