The JESD204 standard is intended for an ADC/DAC interfaced to FPGAs/ASICs. I am not sure it would viable for general chip to chip interconnect since it is specified around converter data and system requirements encountered when dealing with converters. Perhaps it could be adapted though. Maybe we will see a standard for general interconnect evolve out of the JESD204 spec...
do you see 204 penetrate into additional domains other than analog front ends?
what about interface to optical drivers?
what about chip to chip interconnect? having it already on FPGA can facilitate it. standard like that can help IC interfacing.