It finally makes sense for manufacturers to push USB 3.0 RAID. Here's one from Century Japan, the company that is always in the frontier to promote USB 3.0. The SuperSpeed USB RAID-1 likely shares the same enclosure with a similar storage solution equipped with a different interface. Certainly, it won't win any awards home for design originality. From the looks of it, the Century looks quite durable and the two SATA drive trays are secured with key locks.
In terms of configuration, you can setup the Century USB 3.0 RAID cage in one of the following: RAID 0 for a total of 4TB max. storage (with two 2TB); RAID 1 for, well, data redundancy purpose; and JBOD (combining two disks of different size into one partition). There's a toggle in front so you can easily switch between modes. Century claims its cage can do 122MB/s in RAID-1 mode with a pair of Hitachi 1TB 7200-rpm. RAID-0 will boost speed to a jaw-dropping 210MB/s.