SDHC (Secure Digital High Capacity) is a fairly new standard for SD cards that will ultimately provide up to 32GB of storage.
Toshiba has just announced the SD-HC008GT4 card, offering a capacity of 8GB and rated as Class 4 (4MB/second minimum write speed). Before you jump for joy, keep in mind that the device that you plan to use this card with must support SDHC. That requirement alone will leave a lot of devices out in the cold.
The card will go on sale in Japan in January but price was not disclosed.
Source: Engadget