Thanks xeroc for the great history lesson! I was most impressed with this section: Dan told me:
EOS.IO plans to scale by running every contract (application) in its own thread

with private data. Applications will communicate with each other via
asynchronous communication. This is a well-known design pattern that shares
certain philosophies with the sharding approach proposed for Ethereum. EOS.IO
simply places every application within its own shard.
This seems like a stroke of genius. Solves so many problems.