Preview at WWDC likely in June, followed by September launch.
Apple Releases Lightning to SD Camera Reader With USB 3.0 Speeds on iPad Pro
Last month, it was discovered that the iPad Pro's Lightning port supports USB 3.0 transfer speeds, allowing for data transfer speeds upwards of 60MB/s to a theoretical max of 625MB/s. All other iPads and iPhones can only transfer data at USB 2.0 speeds of around 25 to 35MB/s, since only the iPad Pro has the necessary hardware -- a Fresco Logic FL1100 4-port USB 3.0 Host Controller.
Apple has not updated its Lightning to USB Camera Adapter or other accessories to support the iPad Pro's USB 3.0 speeds, but multiple sources have previously confirmed that adapters are in the works. It remains unclear, however, if Apple plans on introducing new Lightning cables that will enable USB 3.0 speeds when transferring files from a computer to an iPad Pro.
Apple's new Lightning to SD Card Camera Reader is also available for £25 in the U.K. and $35 in Canada. Prices vary in other countries.