It appears like the Google Webmaster Central team is testing a new verification process for Webmaster Tools.

A Google Groups thread reports finding the following data in his log file:

Googler, JohnMu, said that this is related to Google testing a new verification process:

Google Webmaster Tool’s current verification process was always been someone awkward for webmasters to get working and share with their clients. So here is hoping to a better system soon!

Forum discussion at Google Groups.