With all the patching and fixing to make ready for Leopard, it's no surprise to see some of Apple's infrastructure tools getting updates this week. Moments ago it was ARD 3.2, and now it's Xsan Admin Update & Filesystem Update 1.4.2! The new software for storage-area networking "addresses numerous issues related to overall reliability, usability and compatibility." Dee-lightful!
Specific patches include FC LUN mounting on Leopard, failover improvements, reduced chance of file system metadata corruption (always good), and support for hosting Xsan volumes on Intel-based metadata controllers. Complete list of features under read more or over at Apple's knowledge base. It's recommended that you peruse the Xsan Migration Guide (PDF) before upgrading your clients; note that the metadata controllers must be running the same (or higher) version of XSan as all your clients, so patch with caution.