Put this one in the sealed envelope. Jeff Bonwick, a Sun engineer who works on ZFS, recently made comments about "general purpose storage." Based on this, I predict that Sun is building a parallel distributed file system, like the Google File System, or Parallel NFS (pNFS). Based on his comments about being "disruptive," I predict that he is referring to a new design, and not something based on the pNFS standard that NetApp, Panasas and Sun are working on.
If Sun isn't working on something like this, they should be. In my opinion, parallel distributed file systems provide much better scalability and reliability than traditional file servers. To add more storage or performance you just need to plug in another system with more disks, and it will automatically be included. When something breaks, the system continues to run, provided that you have enough spare capacity. The failed drive or system can be replaced at your convenience. These two factors mean that you can add more storage as it is needed, rather than buying something big up front, and that the whole system is more reliable.