Hey, all you QuickTime users. Apple has a little present for you. For QuickTime 7.6, Apple brings you APPLE-SA-2009-01-21 QuickTime 7.6 that closes many, many vulnerabilities that reference "arbitrary code execution". Yikes.
Make sure you upgrade to the latest version of QT, because patching the older versions just doesn't seem to buy you much benefit anymore.
Don't waste much time rolling out this new update. Since users typically have feet of clay when upgrading or patching some software peripherals like QuickTime, Flash, Adobe Reader, and so on, evildoers have taken to using them as fertile attack vectors. Just viewing a specially-crafted streaming video or movie file. And we all know how tempted you are to see that free video of Paris Hilton or Megan Fox that gets delivered to your inbox.
If I haven't convinced you yet, let me try again: Secunia PSI is a good, free offering that keeps track of all your software that needs updating or is end of life, meaning no support is available. If you're running a Windows laptop or desktop, PSI is a good investment, if for no other reason than it streamlines notification of problems you need to fix.