I have a few Macs on my desk at work. Two are now running 10.7.1: 17" MB Pro and 24" iMac. I default to Columns view in all finders windows, and I noticed a difference. On the MB Pro, the Finder windows still have their column separators with the little pause-button symbol at the bottom for resizing the columns. On the iMac, though, the columns are now separated by a thin line with no symbol.