At some point, I stopped being able to see Quicktime content on webpages viewed with Safari.
Apple’s Quicktime Troubleshooting page solves this by simply having us download and reinstall Quicktime. Except that yielded no improvement of my particular situation. When I looked into the HD/Library/Internet Plug-In directory I saw the new QuickTime PLugin.plugin that I had just installed as well as QuickTime Plugin.weblugin that was part of the old Webkit and had a date of 2004.
So my next step was to simply quit Safari, remove the older extraneous QuickTime Plugin.webplugin and restart Safari. Upon revisiting the QuickTime Troubleshooting page I was rewarded with this confirmation:
All’s well that ends well. Thanks to this MacWorld thread: