The USB implementers Forum has announced that qualifying companies can now purchase an USB 3.0 developers kit via the USB-IF store. The kits are limited in availability so the USB-If says that each company ordering the kits has to meet certain criteria to order.
If the people qualify to buy the dev kit it retails for $1,500 and includes several devices needed to develop USB 3.0 solutions. Including in the kit are a Pie add-in card based on the NEC xHCI host. A PCIe add-in card based on the Fresco Logic xHCI host, a one meter SuperSpeed USB cable, PDK documentation, and a USB30CV Tool with xHCI drivers.
The development of USB 3.0 requires the use of Windows 7 according to the USB-IF. The kit is intended for companies who are developing peripherals using USB 3.0, not for firms who develop host solutions. It is available now for purchase, assuming you qualify.