I realize that the list all tabs buttons is a toggle, but my fear is that people new to the feature will be lost as to how to dismiss the list all tabs display.
This would be especially true if people invoke it accidentally and don;t even realize they did this by clicking on the icon (think accidental clicks when using the lame laptop touchpad).
I think this needs at the very least a close button in the upper right corner. Also helpful might be a context menu with a dismiss option.
*** This bug has been marked as a duplicate of bug 463213 ***