I used to be a big fan of bitshares, but several problems exist IMO. Namely, no real incentive for market makers exists. Perhaps this has changed. I haven't looked into bitshares in a while, especially after dan larimer moved on. I think EOS has a chance to host a bitshares-type platform that will work.

Decentralized exchanges are coming, make no mistake. I like the idea of performing all operations off-chain except for settlement, which some exchanges, especially ethereum-based exchanges, are attempting. I think idex is one that is trying to do this. This will allow a user experience most closely resembling that of a traditional exchange, with the blockchain-based security properties for user funds.

I need to dig into decentralized exchanges more because that is one of the biggest killer apps of this technology.