Microsoft security guru Michael Howard thinks that Apple's just-released QuickTime update presents one of those OMFG, APPLY THE PATCH!! scenarios. On the heels of the recent problems with these kinds of image-parsing bugs, he might be right.
It's somewhat amusing, in a sad way, that Apple chose to sneak out the QuickTime update on Microsoft's patch day. I've already written about this tactic, which has its pros and cons. Someone just mentioned to me that the QuickTime patch coincided with the MacWorld festivities, when everyone was looking the other way.