I've got a form (see below) with a number of paper-input fields and one paper-dropdown-menu. It looks really buggy and out of place without a label when a value is selected. It's really kind of odd that, once you select a value, the label entirely disappears, leaving the user with no sense of what the field actually represents.

Imagine a scenario where I had two paper-dropdown-menus next to each other with the same set of values (a completely reasonable scenario, say, two dropdowns for current country of residence and country of birth); if they had values you'd have no idea which was which and no way to find out (since you can't undo a selection). That's a pretty significant UI failure.

Instead, the paper-dropdown-menu should support a floating label, much as the does (see the "Floating label" field of https://www.polymer-project.org/components/paper-input/demo.html).