A nice article about ZFS in the Computerworld Blogs: ZFS, a new breed of filesystem
Only one small mistake:

ZFS manages to do this not just with high-end solutions like hardware RAID, it'll do it with standard disks and devices, and, as the name suggests, it'll do it with such limits that are so large, it seems unlikely that we'll reach them any time soon.

You will never reach the limits. There are some physical limits making a storage with maximum size of ZFS impossible. At least you don´t use quarks for storage or transforming Jupiter into a giant harddisk.