For the third time in as many days, this time while I was watching a Vimeo video, and at about two minutes into the four minute video, this pops up over the video. Anyone else experiencing this behaviour?

Apple today announced that downloads of OS X Mountain Lion have exceeded three million in four days, making it the most successful OS X release in Apple’s history. With more than 200 innovative new features, Mountain Lion — the ninth major release of the world’s most advanced desktop operating...

Apple today announced that OS X Mountain Lion, the ninth major release of the desktop operating system, is available as a download from the Mac App Store. With more than 200 new features, Mountain Lion includes iCloud integration, the all new Messages app, Notification Center, system-wide...

Apple OS X Mountain Lion (10.8) in-depth preview -- Engadget What the heck?