New Web Inspector for Safari? If you visit this page, it seems there's a new version of Web Inspector for Safari. (screenshot)

How can I access that?
That appears to be describing Safari as it will exist in the upcoming release of OS X Mavericks. So there are two straightforward ways to get the new Web Inspector:


Become a member of the Mac Developer Program and install the Mavericks Developer Preview
Wait until Mavericks is released to the public and upgrade to it