This week, Adobe released Reader X, the next version that includes a sandbox designed to protect users from PDF attacks.
It's about time...

Reader X on Windows features the new Protected Mode, a technology that isolates system processes, and tries to prevent or at least hinder any malware from breaking out of the sandboxed memory area to do its malicious deeds.

Reader X is also available for Mac OS X and Android, but inexplicably those editions lack the sandbox, so never mind.

It does not makes sense to upgrade at this time, as Adobe code is still riddled with 0-day security loopholes in other parts of the software.
Use Foxit PDF Viewer instead.

Adobe has issued updates to address security flaws in its Acrobat and
Reader products.  One of the vulnerabilities is a critical buffer overflow flaw in a JavaScript function that could be exploited to crash or take control of vulnerable systems.  For the attack to work, users need to be tricked into opening maliciously crafted PDF documents.  Users are urged to upgrade to versions 9.1.1, 8.1.5, or 7.1.2 of Reader and Acrobat to protect their systems from such attacks.  The update for UNIX versions of the products addresses another JavaScript vulnerability that could be exploited to cause denial-of-service conditions or execute arbitrary code.  UNIX users are urged to upgrade to version 9.1.1.
http://www.h-online.com/security/Adobe-closes-critical-Acrobat-and-Reader-holes--/news/113272
ISC: http://isc.sans.org/diary.html?storyid=6385

[Note:  Another busy patch week with Adobe, Apple and Microsoft issuing some biggies. The Adobe one appears to have some widespread exploit code planted on vulnerable websites - should be a priority patch for PCs.]

1USA recommends replacing Adobe with Fox-It .PDF Viewer.   See the File Library.

Please take the time to update as soon as possible.
http://www.adobe.com/go/getflash