Raidsonic has just launched what it claims to be the first external raid enclosure on the market with USB 3.0 support; the ICY BOX IB-RD4320StU3.
This enclosure has room for a couple 3.5-inch SATA HDDs and gives support for RAID 1, 0 and JBOD configurations. The chassis is made from sturdy aluminum and keeps cool enough with the assistance of a 40mm fan.
The unit is of course backwards compatible with USB 2.0, but you won't get all the extra performance on tap without a USB 3.0 equipped PC to connect it to.
RaidSonic says the ICY BOX IB-RD4320StU3 is now available at the equivilent of 81 Euros.