I noticed an update to the WebmasterWorld thread with the discussion of the weird referrals in the form of spam-like referrals coming from Live Search as cloaking tests.

It appears a webmaster is now noticing a bot named MSLIVSOP serving up fake, site-specific keyword referers, as reported earlier. The bot logs the referrer in the form of:

http://search.live.com/results.aspx?q=KEYWORD&mrt=en-us&FORM=LIVSOP

Plus they come from Microsoft IP addresses, the webmaster reports.

Forum discussion at WebmasterWorld.