Save Folder/Tag Visibility State in Navigation Pane
I would love it if you saved the visibility state of the "By Folder/By Data Source" and "By Tag" menus in the Browse Page navigation pane. For me, using tags is the most useful; however, the tag menu only stays open if you have previously selected a specific tag. Also, the folder menu opens up each time you go back to the browse page.
Another idea would be to simply merge the tag menu into the folder/data source menu. However, I suppose if people needed to sort by tag and folder, then they couldn't do that anymore.