He said Google is working on "housekeeping" tasks for that section of Google Webmaster Tools, which implies to me that Google is doing some sort of upgrade in that area.
Over the next few days we're doing some housekeeping in the +1 Metrics section of Webmaster Tools. While this work is underway the data for +1 Metrics will be intermittently unavailable. We expect to have +1 Metrics back online by early next week. Thank you for your patience.
Here is a picture of how the +1 metrics may look for some:
Any guesses as to how major of an update we can expect? Any ideas or wish list items for this section?
We know Google is pouring a ton of resources into the Google+ and +1 products, so honestly, it can be anything. Plus we know it is SMX this week, so maybe an announcement is expected there?
Forum discussion at Google Webmaster Help.