lammert - 11:22 am on Jul 13, 2010 (gmt 0)
Someone from Germany without a WebmasterWorld account asked me to share his experience with the rest of you. I'll copy his comments here verbatim:
I can confirm the original observation: more and more accesses just contain a bare "http://www.google.foo/" referrer. It started on July 1st/2nd (a rise from about .1 percent to about 3 percent of all Google referrers), and judging by the HTTP headers and access patterns, these are definitely legit accesses, not bots, in particular as a possible rel=prefetch access (for top-ranked search hits under Mozilla-based browsers) directly preceding the actual user-driven access still _does_ contain the full list of Google search parameters in the referrer.