According to the technote this update offers a number of fixes:
This update address issues with CLOSE_WAIT states in deployment using JavaMonitor and wotaskd. It also addresses a number of issues related to EOF under high load.
But most importantly it is fully qualified for development and deployment on Panther with Java 1.4.2!
Now all I need is qualified version of Project WONDER..
UPDATE: As noted by Art Isbell on the WebObjects-dev list this release requires Java 1.4.2… and the installer fails with an erroneous error message: "This update can be installed only on Mac OS X 10.3.3 or later." if you are trying to install on Panther with Java 1.4.1.