On OS X, it should be possible to drag around the detached Web Inspector window from empty space in the toolbar, to be consistent with other applications. This used to work in Safari, and works in Chrome since https://bugs.webkit.org/show_bug.cgi?id=71842, but does not seem to work in recent versions of Safari or nightlies. (Also, it should be possible to initiate a drag even if the window is unfocused; not sure what level is responsible for the behavior but Chrome currently requires the window to be focused.)
<rdar://problem/15911038>
Works fine now. We fixed this.