People talk about it all the time, no companies talk about it. Unless the voltage gets dropped to nominal 3.7v you will not see Lipo used in 12th scale. At that low voltage (single cell) most people will need to run a receiver pack. If that is the case, how much money are they saving, or how many headaches are they avoiding? Even with a 2s receiver pack, you will need a lipo regulator so that you don't kill your electronics.

With the reduced voltage comes reduced rpm, both directly related...

I like the idea of reduced maintenance in 12th scale, but not the smoke and mirrors kind of reduced maintenance. Receiver packs are just another thing to monitor all the time. This is also an issue for people that want to race World GT, as the rule set for that division is 4 cell NiMH.