Been using OS X 10.7 Lion since early developer previews and there is this bug (or feature that's not implemented). Clicking Inspect Element/Web Inspector of the Develop tools will always pop up the Web Inspector window. It used to be stuck or used to remember my preference and used it as default.
It is docked by default on Chrome and FireBug is well docked in Firefox and it was docked by default (or remember my settings) in Safari 5 on Snow Leopard.
Anyone faced this issue and have a fix?