I don't think RCers have much to worry about. We generally fly away from highly populated areas and away from power lines. We have relatively strong RC signals and very narrowband receivers. Propagation at 72 MHz is rarely more than line-of-sight, so any interference we receive from BPL will be limited to whatever is radiated in the immediate area.

It's the ham radio operators, particularly those who do HF DXing, that will get shafted. If BPL becomes popular the noisefloor over the HF spectrum will rise, and this will be worldwide, not just limited to the immediate vicinity of the source. I have worked Japan with less than 1 watt. Worlwide propagation over the 3-30 MHz range is common.