One of the better explanations of blockchains, Bitcoin and Ethereum I've seen. mk
We are a long long way from much of that, as the technology simply isn't there. The blockchain works fairly well for finance, because the data has a small footprint. I have no idea how Ethereum will not be crushed under its own weight.
It's worth noting that Mike Hearn's Lighthouse has been launched. IMO that is an interesting use case. OpenBazaar is potentially another one. The fact that bitcoin is programmatic money (it can handle multisignature transactions on its own) creates some compelling use cases.
I also think the possibilities that it opens up for most of the world that isn't banked are huge. The fact that you only need a cell phone to transact with anyone anywhere means that most of the world can leapfrog over the bank + credit card system.