Whether ZFS was announced at this event has no bearing on whether it's in Lion or not. As you might deduce from the set of features they did cover, this was for the media and public. ZFS is completely uninteresting to them. I guarantee you there will be a ton of back-end changes, but they will never be announced at something like this. We'll see more of that kind of thing at WWDC next year.
But despite all that, dollars to doughnuts ZFS won't be in there. But because of ownership issues, not because it wasn't announced today.
I still have not figured out what is the actual legal situation of ZFS. Who can use it and at what conditions? Also is now Oracle the "owner"? So confused. I'll dig.
But despite all that, dollars to doughnuts ZFS won't be in there. But because of ownership issues, not because it wasn't announced today.