This is only layer1 (like IP in the networking world). Wait until layer2 comes (Lightning Network, TumbleBit), then we will reach the scalability levels we need for the entire planet to use the same blockchain.
Err, each layer on top of IP slows down traffic, not speeds it up. The extra overhead and retransmits result in less useful data being transferred with each packet.
Depends on what you mean by speed doesn't it? Segmentation via additional layers certainly speeds up the network as a whole. I thought the ability to scale via adding additional layers is why SDN took off.
