I'm afraid this interface is both too subtle and irritating.
As a user, when I perform an action with potentially serious consequences, I wait for something obvious – like a pop-up. The pop-up may seem elegant, but it must be invasive enough to get my attention.
The other problem if I have to click the same button, but wait a certain interval before doing so, so I'm embarrassed. It's really irritating when I have to wait for software. Of course, it may take time to move my mouse to a pop-up window, but at least I'm doing something and I do not feel compelled to wait for the software.
I think pop-ups are the way to go. State-of-the-art user interfaces are acceptable as long as they perform the task, but when an action has consequences, the function must take precedence over the form. The purpose of a confirmation is to attract the attention of the user, so that he opposes the subtlety.