I've got an 80 Hunter and 'Lock myself... I'd *love* to see this happen as well. TrackIR kiting in BGs and ARENA would be spectacular.

I spent over a year pushing them to integrate TrackIR in 2008/2009. There were some devs at Blizz that were intrigued, but with simultaneous development on Cataclysm, Diablo 3, and SC 2, their QA department was eternally swamped. And apparently all new device integrations have to be vetted by QA before developers can start integration. This is where we hit the bottleneck with them.
I'll start drumming up conversation with them again, if at all possible. From your end, I'd recommend hitting up their forums with a descriptive suggestion on what you'd like to see implemented, and how. Including a link to a YouTube video of TrackIR in, say, Arma 2 could help as well. Then, call and write emails.