Just noticed these, new column headers in list view.
They're like this in Lion, but only if you arrange the icons by name (as opposed to just sorting them). Is it the same in Mountain Lion, i.e., do the column headers look different if you choose Arrange By: None?
I wonder why it's not actually arranging the icons by name anymore, just sorting.. (if you arrange by size or something different you'll see what it should look like)