The global insurance industry replaced with autonomous smart contracts able to provide 10x value, at 10x cheaper cost than any current provider. Escrow services instantly replaced in the same fashion. Global marketplaces more nimble, efficient and cheaper than Uber, Airbnb, eBay and KickStarter (to the point where they will be forced to decentralize themselves to remain competitive). Distributed, autonomous hosting, DNS and CDN services that vastly outperform giants like AWS, ICANN and Cloudflare.
And that's just the low hanging fruit.
It will be many years before it reaches critical mass and invisibly seeps into mainstream ubiquity. But just as Bitcoin and the Internet cannot be shutdown, the Ethereum Genesis block will be an irreversible Singularity.