There's now a standard data transfer method over USB that combines MIDI 2.0 and MIDI 1.0 data. So, why does this matter?
· Better support for high-speed throughput (up to hundreds of times MIDI’s original speed)
· Old and new devices work with any operating system that supports the new USB Class Definition for MIDI Devices
· As with the previous version, no drivers needed for compliant devices
· Supports up to 256 MIDI Channels in 16 Groups
· Can provide more accurate timing for dense MIDI streams
· Over time, simpler to implement than USB MIDI 1.0
· Enhances using MIDI 2.0 mechanisms including MIDI Capability Inquiry (MIDI-CI)
· Added support for Interrupt transactions for better control over jitter and throughput
There's more info in the MIDI Association
forum, as well as a link to download the spec if your hobby is MIDI rocket science.