I called up traxxas for the hell of it and this is what they told me:
"we dont plan on releasing one because there wouldnt be a high enough demand in the sport world. Also, there would be a large amount of retrofitting to the rustler, in other words, the rustler would'ne be able to handle it with out significantly beefing up the drive train"
I personally beleive this is BS. They should come out with a 2-speed.