Along with the announcements today of the iPod Shuffle capacity bumps and XSan 2, some users are realizing that Apple's Xserve RAID solution has completely disappeared from Apple's online store.
In addition, the Xserve RAID product page (http://www.apple.com/xserve/raid/) now redirects to http://www.apple.com/server/storage/, which promotes a 3U external RAID enclosure by Promise. Apple has added the Promise RAID solution to its store and now presents it as the external RAID choice when configuring an Xserve.
External Storage
For massive storage needs, connect a Promise VTrak E-Class Fiber Channel RAID subsystem to your Xserve. The VTrak E-Class provides high performance and high availability through 4Gb Fiber Channel and dual active/active controllers. An Apple Fibre Channel card for connectivity is required.