I guess I'm looking at it from a completely selfish 1/12 racer (kinda like all the completely selfish sedan racers that pushed their LiPo/Brushless/whatever agenda on us) and my question is "what would make the BEST 1/12 formula?". And getting that enormous chunk of weight off the back of the chassis would be a HUGE start.
I don't buy for a minute that a different motor for 1/12 vs sedans and whatever would be a deterent for racers.
As far as manufacturers...the rumor I'D heard was that ROAR is a "racer-driven" organization. I also think the mfr's would come to the party if we, the 1/12 racers, created a groundswell. Hell, there are probably appropriate motors out there right now if we start with sensorless.
I maintain...if we're going to re-design 1/12 chassis anyway to incorporate LiPo, let's do the WHOLE job instead of piddling away at it.