Just flew LAX-IST-LAX on the 77W in Y - there are regular jacks that will take different plugs as CAlex mentioned - looks like there are 2 plugs for each 3-seat section.

There's also USB, Ethernet, and serial cable connections on the seatback, but not sure what the latter 2 are used for at the moment. The USB charged my iPhone just fine, but the connectivity to the IFE was not working on either flight.