For the past few weeks I have been hearing reports of Google not underlining the titles of the search results.
That conversation recently seemed to have spiked up and more and more people are now seeing, well - not seeing, the underlined titles in the Google search results.
@andrewchen were some of the few to tweet about this and include a screen capture.
Google search results without underlines:
Google search results with underlines (like most people see them):
At first it I thought this might be some type of extension removing the underlines from the title but with the number of reports I am now seeing, this has to be some type of limited Google usability test.
Forum discussion at WebmasterWorld.