A local company that was an early adopter of many of the things you guys are talking about.
Mesilla Valley Transportation
Their first super singles on trailers looked pretty scary, they sat in too narrow and the trailer would rock pretty bad on even calm days. Now it looks like they are getting either a different offset on the rims or are getting trailers with wider axles to make up the difference.
They have a few with the colapsable boat tails on their trailers, but by in large the only visible mods are... Smooth covers on the drive wheels, trailer skirts and super singles in place of the duallies on both the trucks and most of their trailers.