Some of you, especially those with Intel graphics, might have been experiencing the very frustrating situation of installing the latest viewer update, only to have the viewer crash repeatedly at the "initializing VFS" step.
Linden Lab has developed what (they hope) is a fix for this, although I caution that it has NOT yet been fully tested or approved as an official release.
If you want to try it, here's the download link: http://automated-builds-secondlife-com.s3.amazonaws.com/hg/repo/oz_maint-4678/rev/296857/index.html
Use the CYGWIN version for Windows, the Darwin version for Macs, and the Linux version for...uh, Linux, of course.
UPDATE: Two new developments. First, the latest AMD/ATI Radeon graphics driver is causing problems for some people. If you experience this, revert to an older driver.
Second, the "fixed" viewer is now available here: http://wiki.secondlife.com/wiki/Linden_Lab_Official:Alternate_Viewers Use the Second Life Benchmark Viewer version 220.127.116.117128