The update fixes the following problems:
- Address an issue that may cause the system to become unresponsive when playing a video in Safari.
- Resolve an issue that may cause system audio to stop working when using HDMI or optical audio out.
- Improve the reliability of Wi-Fi connections.
- Resolve an issue that prevents transfer of your data, settings, and compatible applications to a new Mac running OS X Lion.
I hadn't experienced any of these issues, but it's good to know I won't know. If you were waiting for the first update to make the upgrade to Lion, now your chance.
via MacRumors
