"active cables are commonly used at data rates above 5Gbps. These cables contain tiny chips at either end that are calibrated to the attenuation and dispersion properties of the wire between them. Compensating for these properties "greatly improves the signal-to-noise ratio" for high-bandwidth data transmission."
In a few years it will be everywhere natively: competition will have driven the parts cost to pennies per board, and average customers will be demanding it.
2. This also gives them the ability to have longer haul optical cables without changing the motherboards, the optical transceivers will be inside the cable.
3. None of the ESATA ports on any computer I have ever owned has never seen a plug. All of the firewire ports are empty. Probably 2/3 of the USB ports are empty. If Thunderbolt goes the way of these, why not move the circuitry out of the empty ports?