I've been looking at large NAS systems as well, prices are all over the place... You'd probably be looking at close to $100k from someone like Dell for a Raided NAS that size (2 x NX4), while you could spec out one from "Digiliant" for less than $30k... http://www.digiliant.com/default.php?cPath=80_46_130&os...
Drawing from the above advice and the responses to my other post here though, if you're not looking at DIY solutions you might want to look at the systems from DNF Storage. Seems they can come pre-configured with ZFS and RAID-Z2.
I heard some very good prices from a company at SigGraph whose name I can't recall at the moment. They had developed a special rack drawer that mounted the drives vertically inside the drawer. The result is they could fill the entire depth of the rack with drives, and have everything logically closer to the controller. I'm roughly guessing at the actual density but I think they could fit the entire 96TB in 10U worth of rack space, plus some. (Well, then you need the redundancy, but could mean the difference between one full rack and three.)
They claimed massive throughput, but of course they were probably employing the usual tricks where they claim throughputs that they get using 15k SCSI or SSDs, alongside capacities they get using big SATA drives.
I believe they were quoting dollar figures lower than the $100k.
Wow I just clicked on the Polywell link supplied by jtric. I don't recognize the name, but either that's the same company or they developed the same solution.
What I wonder is what happens when you have to pull the drawer out to replace a drive, and accidentally pull the cable connecting the whole drawer...