Yep, while the code push is ongoing, there may be a few blips here and there. I think we're pretty much back to normal now, though!
Yes -- if you look at the comments to the more recent dw-maintenance entry you'll see some discussion. The change is to make things display more usably on small screens. The overflow-to-1-column only happens on smaller screens -- it's designed to only kick in at around 640px or so -- so if you're viewing on a desktop or laptop computer, you can make it stop overflowing by making your browser window bigger.