Thunderbolt represents a large leap in peripheral data transfer; both through speed and functionality. Thunderbolt offers bidirectional, dual-channel use at 10Gbps with both PCIe and DisplayPort protocols. In addition, Thunderbolt is compatible with existing DisplayPort devices and can be used to daisy-chain up to 7 devices together with electrical or optical cables. Thunderbolt has low latency with highly accurate time synchronization, uses native protocol software drivers, and supplies power over the cable for bus-powered devices such as some external harddrives.
Seen here is a sample block diagram showing the controller connections for thunderbolt. Thunderbolt is not compatible without Intel's thunderbolt IC chips, except for the end device on the chain of devices, given that it is using a mini DisplayPort or has an adapter with a built-in thunderbolt controller chip.