After some very embarrassing reports, they quickly backpedaled and released a program to undo the damage. You can download it here.
Sony, and others, have a long history of experimenting with copy protection schemes. The most recent attempts involve distributing a "multi-session" CD, containing audio tracks and a data track. When inserted into a Windows PC, the "autorun" file in the data track installs a software wedge that hides the audio tracks. This forces you to play DRM-protected versions of the songs, contained as data files.
This is nothing new. Sony's latest version, however, takes steps to hide the existence of the wedge. And it installs itself in such a way that removal will permanently cripple Windows' ability to play any audio CDs. As far as I'm concerned, this is no different from a virus.
Fortunately, there are plenty of workarounds, if you're careful. The easiest way is to not use Windows. All other operating systems (Linux, Mac OS, etc.) will not auto-run the installer, and is incapable of being run manually. Without the software wedge, the same programs that play/rip normal audio CDs will work on the protected disc.
If you're forced to use Windows, the thing to do is make sure the auto-run facility doesn't run. Holding down the SHIFT key whenever you insert the disc will do it. You can also disable this permanently in several different ways, depending on what version of Windows you are using. This will have the side effect of preventing all your data discs from auto-running, but IMO, this is a good thing.