Quoting from the Phone Scoop article:
The Power Matters Alliance and Alliance for Wireless Power today announced they will work together to make their wireless charging standards compatible. According to the agreement, PMA will adopt the A4WP's Rezence specification for magnetic resonance in both the transmitter and receiver of chargers and devices. The A4WP will adopt the PMA's inductive specification as an option for multi-mode uses. Both groups will work together on an API for network services management.
According to the new alliance, "This is a significant win for consumers, who will eventually benefit from a wider range of devices that work together." Personally, I see it as a last ditch attempt to gain any kind of traction in a world dominated by Qi wireless charging successes from giants like Nokia and Google.
It's somewhat sad that three non-compatible standards exist in the first place, of course, but if you had to pick a winner then Qi is the obvious bet. Think back to VHS vs Betamax, if you're old enough. Qi is the VHS in this scenario - simpler and arguably less capable, but found in far more devices, at least in the phone world.