CAN bus would probably fix the latency/bandwidth issues with serial MIDI, and it side-steps the device/host problem and the short cable problem with USB. I'm in favor.
(I'm actually working on a MIDI controller. It has a CAN bus interface in addition to serial MIDI and USB. I don't have anything to talk to over CAN bus yet, but it's sort of there for future development. I probably won't send actual MIDI over CAN bus, but rather a protocol yet to be designed that's sort of like MIDI but less piano-centric.)
(I'm actually working on a MIDI controller. It has a CAN bus interface in addition to serial MIDI and USB. I don't have anything to talk to over CAN bus yet, but it's sort of there for future development. I probably won't send actual MIDI over CAN bus, but rather a protocol yet to be designed that's sort of like MIDI but less piano-centric.)