The update for the Sensation is 9.21MB, and includes "an important security update. HTC urgently recommends you to download and install this update."
So, shame on HTC for allowing such a huge security vulnerability to pass through the supposedly rigorous testing. But good for HTC for being so quick to implement a fix, and for listening to the developer community who found this bug to begin with.
Now, in case you are not rooted, or running a stock ROM that doesn't have HTC Loggers already removed, it's just a matter of playing the waiting game.
[Android Hilfe via Android Police]