A reader of AppleInsider has unleashed pictures of an unreleased prototype of Apple's Xserve RAID. While externally the new prototype looks much the same as the existing model, the prototype was configued with SATA drives (rather than the current Xserve RAID's UltraATA bus), and had 6 Fibre Channel ports (up from the current version's 2).
While the admin software (listed at version "2.0d32 dev/A3.10", up from 1.5 in the current model) was mostly disabled, AppleInsider muses that the additional ports may be for more flexible drive access.
On the currently shipping Xserve RAID, when one Xserve is connected to both ports it has access to all 14 drives. When two Xserves are connected (one to each port), both have access to 7 of the drives. It's likely that newer RAID Admin software will allow arbitrary assignment of drives to any of six connected Xserves. It is also possible that these newer Xserves RAIDs have an integrated 6-port fibre channel switch. This won't be known until an actual release of the hardware when new firmware and admin software is available.