A new WebmasterWorld has reports from a couple members who have seen this behavior from Google recently.
A senior member said:
Today, for the first time, searching on google.com I noted that Google "suggests" me the most requested phrases.
I thought I clicked the wrong bookmark ( I have a boomark for googe.com and another one for Google suggest), but in fact the "suggestions" seem the default choice...
It can be that this user went to Google Experimental and clicked on the "Join experiment" button under "Keyword suggestions."
However, this searcher said he did not join that experiment.
Forum discussion at WebmasterWorld.