Polywell announced NetDisk 8000v, which can be configured with Windows Home Server or Linux should you wish. The 8000v is a tall tower unit, offering (count ‘em) 8 hot swappable drive bays, which will get you up to 12 Tb of storage if you popped a 1.5Tb drive in each of them!
You can purchase the unit pre-configured with 4Tb ($1699), 8Tb ($2599) or splash out on the 12Tb system ($2999) if you’re feeling flush. The included memory is low, so you may need to upgrade if you wanted to run a number of add-ins.
More info: Polywell