The new update introduces fixes and tweaks for a number of applications included in OS X: iPhoto, Finder, Safari, Dashboard and several other applications. More critical updates include drivers for wireless access, which has been causing a number of users to experience random disconnects and signal drops on the MacBook Pro, MacBook and iMac computers. Apple identified that several of the included system updates would improve performance in Rosetta as well.
If you are an Apple user and love keeping up to date, then get on er! More discussion on the updates can be had here.