I didn't think to try the abs benchmarks in rubinius when I wrote up my first looking back post. A bit later, I decided to give it a whirl, and the script worked (minus a bug in the real time column). Here are the rubinius results:
$ shotgun/rubinius benchmarking_abs.rb user system total real ternary: 0.985418 0.000000 0.985418 ( nan) explicit: 1.039927 0.000000 1.039927 ( nan) implied: 0.824196 0.000000 0.824196 ( nan) system: 0.821973 0.000000 0.821973 ( nan)
Not quite as good as Ruby, but comparable or better than JRuby (interpreted and no special switched). I'm intrigued that the implied version looks better than the ternary or explicit (and in line with the system) though.