The Viperlair has an interesting article on the future of Storage. It is Native Command Queuing, which means that the hard drive can have the request que altered in order to be more efficient:
Native Command Queuing (NCQ) was developed to address the problems of Legacy Command Queuing (LCQ). Introduced with the Serial ATA II spec, this is a feature that can only be found in native SATA hard drives. Unlike LCQ, NCQ works by allowing a drive to process multiple commands at the same time. These commands can be rescheduled or reordered on a whim, and can also issue new requests while the drive is retrieving data from the previous request.
Native Command Queuing & Seagate's Barracuda 7200.7
Take Care,
Richard