1) USB3 has a 1 year lead - check out how many products are out already
2) 5Gbps vs 10Gbps. There are just a couple of SSDs that need SATA III (6Gbps) because the 3Gbps isn't enough. You just don't need the speed for disk I/O. What for then? Current DisplayPorts 1.2 has 17Gbps so I don't really see the Thunderbolt replacing it.
also Firewire 800 was substantially faster in theoretical and particularly in practical throughput