Thunderbolt is a familiar-looking port, a brand-new chip, and a cord, which allows devices to pipe two data streams simultaneously in both directions with over a single cable at up to 10 gigabits per second to start, primarily using PCI Express x4 for data and DisplayPort for video. The Thunderbolt controller chip is required for the system, but Intel says it's hardware-agnostic and doesn't require an Intel processor or chipset to use, similar like a miniature router of sorts that rapidly switches between the two bidirectional channels of data.
Intel Thunderbolt previously was known as Light Peak, the Thunderbolt will be shipped together along with new MacBook Pro model. Intel also reinforces that this is compatible with existing DisplayPort devices and it also uses the PCI Express protocol for enhanced compatibility. Daisy-chaining will be possible, along with bus-powered devices, and cables can be made using either optical or electrical construction.
http://www.engadget.com/2011/02/24/intel-thunderbolt-a-closer-look/