Here is a screen capture of that in action:
I have emailed Google for a statement and I will update this post when I receive one.
If you want to discuss this with other SEMs, just the Sphinn thread.
Postscript: Here is a statement I received from a Google spokesperson:
As part of our ongoing commitment to innovation, we are currently running an experiment in which users can customize the ads that appear in the “Sponsored Links” section of the search results page by deleting ad results. This experimental feature is only visible to a small number of users, and we have no news to announce at this time regarding developments in our AdWords product offering.