Over at Quora.com a question was posed - "Network Attached Storage: What are the current top-of-the-line NAS/Storage solutions for the home?" I think the answers posted so far are interesting because they show what a wide range of options currently exist for NAS type home solutions - from Synology Drobo, and QNAP hardware devices to software solutions such as FreeNAS.
One of the answers that focuses on FreeNAS describes the benefit of the ZFS file system:
If you are comfortable of installing and configuring OS by yourself, I suggest you to FreeNAS or FreeBSD, in which ZFS is a killer feature for a home NAS. I've installed FreeBSD+ZFS on a HP ProLiant microserver, which is a decent server for home usage. The most important feature of ZFS for me is its supporting of "scrub" operation, which might be able to find silent occupations on your disks and fix them. All RAID levels can not provide such guarantee for your data safety.