Spakman, I'm very excited about this. And I say this as someone who's writing his own ruby shell/shell-complement. Mine is mostly intended to be invoked from Bash the way you'd invoke grep, though it can also be run interactively, where it behaves like irb. The one clever thing I did is allow you to avoid escaping by putting your ruby command after a # on the bash command-line. Bash then ignores everything after the #, and crush (my shell) grabs the last line in the bash history and evaluates the part after the #.

I will definitely be trying out your shell. If you're curious about mine (feel free to steal code, no promises that everything works as committed): https://github.com/afiler/crush