Have you heard about Multi Polyphonic Expression ? Roli, Roger Linn, and number of other companies have proposed a way to do per note controllers.
Multidimensional Polyphonic Expression (MPE): A specification that allows compatible music hardware and software – including controllers, synthesizers, and digital audio workstations – to interoperate more expressively by using MIDI channels to control pitch, pressure, timbre, and other parameters in each note of a polyphonic performance.
The MIDI Manufacturers Association (MMA) has formed an MPE working group to discuss how to make this an official part of the MIDI specification.
The MIDI Manufacturers Association never publically discusses the details of MIDI specifications until they are officially approved because that can cause market confusion and interoperability problems.
Imagine some of the details of the proposed MPE spec were discussed here, someone then made some software based on those specs, but then at the last minute the working group decided to change the way the protocol worked. That could get messy quickly.
So although we can't reveal any details of the actual MPE messaging, we can talk about what MPE could do and what features people who use MIDI would like to see it enable.