Is there a good technical article explaining exactly how the 2012 traction control system works somewhere? I mean, like does the system just look at the relative wheel speeds or does it measure wheelie altitude/rates and/or bank angle. I'd really like to know a bit more about what this thing is actually doing in the various modes.

It's not measuring wheely heights.Bank angle...no.Compares front to rear wheel speed...adjusts accordingly.Uses ignition adjustments and secondary plate functionings to control the corrections.(fueling).Mainly timing.Google "Kawasaki KTRC on zx14R"...that might steer ya in the right direction .

The TRC on the new 14 is not only reactive, like most other TRC systems, but is also predictive, analysing data from numerous sensors on the bike every few milliseconds and (probably using algorithms) using it predict traction loss and the rate at which it is ABOUT to happen and so pevents it happening in the first place. This means the system is much less intrusive to the point of being virtually undetectable unlike lesser systems which detect rear wheel slip than cut power off/on/off/on etc...
Try googling Kawasaki KTRC.