Thunderbolt > Displayport
Thunderbolt isn't essentailly just Displayport. What Thunderbolt has is a backward compatibility mode where chips will drop back to Displayport mode if the only thing they see is a display. What Thunderbolt is, is encapsulated PCIe. In a sentence, you take all the good ideas from Firewire: hot plug, dynamic reconfiguration, peer to peer communication, isocronous transport, and use it to wrap around a PCIe lane or two as payload. Pretty much exactly the best of all worlds.
This means some pretty interesting things can happen. One of the neat tricks is that Thunderbolt is not difficult to port a peripheral to. A PCIe lane pops out at each end, and all the work done on previous device drivers should be trivially ported. Amongst other things it neatly subsumes the role that Express slot had. But better.