The old AdSense interface is gone for good, as of yesterday, so holdouts clinging to that version are being thrust smack-dab in the middle of the new AdSense. Users had previously been able to toggle back and forth between the old and new versions of the interface.
Publishers have certainly had plenty of warning. Google began testing the interface as far back as November 2009. It was released to all publishers in November 2010, and Google warned in September that the old version would soon be sunset.
Still, some in the Webmaster World forums complained about the change, while others said they’ve grown accustomed to, and even like, the new version. Over the last two years of testing, Google has continually made tweaks to the interface in response to user feedback. Here’s the latest official guide to the new interface.