Routine Mac OS X updates are becoming just as common as Windows updates, likely the inevitable result of the increased popularity the OS has discovered the past few years. The latest update issued this week has patched up a huge number of flaws, ranging from minor issues like program crashes to a relatively high number of "serious" exploits that could lead to broken and infected systems.
Patches for the Mac OS X kernel affected shared systems in which a user could access files they don't have permissions to, another update fixed an issue with unencrypted network passwords, a fix in Time Machine will prevent "sensitive" data from being leaked out of backups and a laundry list of others. This update is quite large, and contains many important updates, so if you are an OS X user it is a good idea to update right away.