It’s a redesign for this place, a modified version of the new Ryu theme: a much-needed behind-the-scenes upgrade and a maybe-not-bad change in the look of things. E.g.:
For those of you into WordPress, I now have options like post formats, responsive parameters, featured images (such as the gif above), a click-down “sidebar” at the very top of the screen (that’s what those tabs are if you hadn’t tried them), etc.
Now I just have to think of stuff to publish here.