Western Digital's new My Book Studio Edition II has 6TB on offer, but no Thunderbolt or USB 3.0
If you want a lot of the GBs in not a lot of space, 3TB per disk is about as good as you're going to get. Western Digital has slapped two of its triple-terabyte monsters into a dual-disk enclosure and paired it with eSATA and FireWire 800 interfaces to create the My Book Studio Edition II. There's a good 'ol USB 2.0 hole in there as well, but no USB 3.0 or Thunderbolt for those getting hip with the new connections. Time Machine support is baked in as well as your choice of RAID configurations, all at a cost of $549.99. That's a good bit more than you'd spend if you bought a pair of disks and an empty enclosure, but such is the price of convenience.