Might be an idea to start working on this (even I can do this ;). I was browsing through my bookmarks, and found an old one leading to the ruby version of PLEAC, which had been of great help when I started with ruby.
I think this would be a fun and useful project for the community and any newcomers. There is already a scheme dialect in the top 5 languages, Guile.
I don't know the best way to begin. Maybe add it to Anarki with a link to the perl code for now. I think it's a huge undertaking and could progress pretty slowly if PG doesn't actively develop arc. But at the same rate it could be really useful to find arc's weaknesses.