Pretty small update only only includes a few main fixes as listed below:
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.
Nothing about my crazy mail issue I am having though.