BitShares introduced

DAC (Decentralized/distributed autonomous company) and the platform for running DACs are
quite strongly associated with BitShares. https://letstalkbitcoin.com/bitcoin-and-the-three-laws-of-robotics/
Although may blockchain projects qualify as DAC, the economy of running it has influenced the BitShares system.
It is yet to gain some presence and understanding (including my own) but some DAC projects are already there
in the BitShares blockchain (like PLAY of http://playshare.io/).

DPOS (Delegated proof of stake). http://wiki.bitshares.org/index.php/DPOS
There are currently top 101 delegates  (voted in by stakeholders) who produce blocks.
They may choose to burn (part of) the reward for producing a block thus stopping dilution and preserving the value.
Or they may keep the reward and add value to BitShares in some other way (developing, marketing etc).
The block production under 10sec is quite handy for an inbuilt decentralized exchange.

TITAN (Transfer Invisible To Any Name) http://wiki.bitshares.org/index.php/TITAN
It generated a new key pair (deterministically from the owner key) for each new transaction.
Useful for some cases but complicates things in others (like having same wallet/account on two machines).