It's all clear. Sun' CEO Schwartz was both right and wrong and Apple marketeer Brian Croll was wrong.
Contrary to the statement of Apple's Brian Croll, a senior marketeer, Sun's ZFS filesystem IS in Leopard, the coming release of Mac OS X. Sun CEO Jonathan Schwartz was right to say that ZFS was in Mac OS X, but wrong to say that Steve Jobs would announce it at the Apple world-wide developer conference.
Leopard, or Mac OS X v10.5, will use two filesystems: the current Apple HFS+ one used in Mac OS X v10.4 (Tiger), and Sun's Zettabyte File System (ZFS). The default filesystem will be HFS+. In Schwartz' Sun Blade Module System launch presentation he said Apple is announcing this week at its world-wide developer conference (WWDC) that: "ZFS has become the file system in Mac OS 10." He was wrong in that precise point too. ZFS isn't 'the' filesystem in Mac OS X v10.5.
Of course in may well become 'the' file system in a subsequent version of Mac OS X, v10.6 or v10.7 perhaps. But Apple isn't saying.
What Apple's Brian Croll did say was this: "ZFS is not the default file system for Leopard. We are exploring it as a file system option for high-end storage systems with really large storage. As a result, we have included ZFS - a read-only copy of ZFS - in Leopard."
"Read-only means that at a later date, if there are ZFS volumes, those systems would be able to read ZFS volumes. You cannot write data into the system. It will allow you to read ZFS volumes later."
Croll wouldn't say if ZFS would feature in Apple's Xserv server products.
ZFS will allow huge filesystem capacities and protect data stored in it much better than current filesystems.