InterTwined
Banido
The benefits, especially in the mobile space, are numerous. HHDs will be able to boot or resume operation up to twice as fast as a traditional hard drive, and are five times as reliable. Additionally, the drives provide an extra 20-30 minutes of battery life over their predecessors.
Hybrid hard drives eliminate the need for the disk to spin continuously, which would contribute to a longer usable life as well as less risk of data loss from dropping or jarring. This is due to the NAND flash memory acting as a cache.
http://www.betanews.com/article/Hybrid_Hard_Drives_to_Debut_at_WinHEC/1147898593