According to Trend Micro and their Zero Day Initiative (ZDI), Apple has deprecated QuickTime for Windows. This means they will no longer fix security vulnerabilities.
This is interesting as I have been asking Apple, through their security email address and their new Twitter support system, whether they'll be extending QuickTime beyond Windows 7 (see https://altonblom.com/s35e03/
Here's what Trend Micro had to say:
Apple is deprecating QuickTime for Microsoft Windows. They will no longer be issuing security updates for the product on the Windows Platform and recommend users uninstall it.
In this instance the only workaround is to uninstall QuickTime.
This may be interesting as QuickTime has been an important component for iTunes to work correctly, especially with videos.
I'm still awaiting confirmation from Apple, however this may not come any time soon.