First, let me say I think the Pi Zero is an excellent board, the price/performance point is incredible (if I could find one to buy).
But I think the lack of data on the power port is kinda sad. After all, it has only two USB ports on it and only one can do data. If the Power Port also did data, it would make it much more versatile.
For instance, you could plug it into a powered USB hub and over only one cable be able to power and communicate with other peripherals.
Or if used as an intelligent controller, like on the LutzBot Mini 3D Printer, just plugging it into the USB port on that printer and you'd have power and data without needing another power supply and cable.
It would make using the Pi Zero and an embedded IoT intelligent device that much simpler.
Just my opinion.
Maybe the next generation (0+, /0, 0^2 ?) will have this feature...