SD Association has announced the UHS-II Standard and a new eBook Specification (press release PDF).
"New pin design ratchets bus speeds up to 312 MB/s, eBook spec opens books, graphic novels to secure portability"
This is "... a new, dual-row pin memory card design achieving bus interface speeds of up to 300 megabytes per second for SDXC and SDHC devices and memory cards. It is fully backwards compatible, allowing equipped devices full use of any SD, SDHC and SDXC memory cards."
"New high speed interface signals will be assigned on the second row of pins of select SDXC and SDHC memory cards offering the new speed. This option will be available in both full-size and micro form factors and does not change the physical size or shape of the cards. This design will be part of the forthcoming SD 4.0 specification, expected in early 2011."
Read the SD Association Defines New High-Speed Performance Options for SDXC and SDHC Memory Cards and Devices press release (PDF) for more information.