If Apple were to implement this, I'd imagine it would be N x TB3/USB3 USB-C format ports, an ethernet port and maybe HDMI (though a dongle would possibly negate that – if 2.1 can be achieved that way)
Otherwise, looks good to me.
If you really wanted to do it, the biggest processors have 40 lanes of PCIe. Intel's Xeon E5's can be dual-socket mounted, for a total of 80 PCIe lanes. Adding PCIe switching, like two Avago/PLX PEX9797s (see http://www.anandtech.com/show/9245/avago-announces-plx-pex97..., particularly the diagram at http://images.anandtech.com/doci/9245/Slide14.JPG) can get you there in the end.
But the sacrifice is that you actually only have 80 lines of PCIe, and it all has to be coordinated. Dual-socket computing does not quite double your processing power, and a switch adds latency. Your overall bandwidth will still be limited to what you have coming from the processor.