The update addresses a few issues.  It also appears to incorporate the recent Migration Assistant update.  It is available via Software Update and weighs in at a small 17.4MB on our MacBook Pro Late 08.

The 10.7.1 update is recommended for all users running OS X Lion and includes general operating system fixes that enhance the stability and compatibility of your Mac, including fixes that:

– 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

For detailed information on this update, please visit this website:http://support.apple.com/kb/HT4764.

And the new Mac Minis and MacBook Airs get their own update.  Here are the changes on that.

  • 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
  • Resolve an issue where MacBook Air may boot up when MagSafe Adapter is attached
  • Resolve an issue causing intermittent display flickering on MacBook Air
  • Resolve an issue that causes the SD card slot in Mac mini to run at reduced speed with SD and SDHC media