Care to elaborate on the competing feature-equivalent standards?
There is really none. The current state is that each different display driver supporting different sorts of LCD panels, bridge chips, etc, has it's own framework for panel drivers. Meaning that if you implement a driver for some particular brand/model of LCD panel on one SoC, you can't just re-use the driver on another SoC. Which is an obvious duplication of effort, so a common framework will be a nice addition once the details are hammered out.