Executables in bin folder conflict with their gem versions.
It would be nice if the executables for rdoc, rake, ri, etc. locate in bin folder, would be standard RubyGems stubs. Otherwise, once there is installed version of such library as a gem, the original file is rewritten and the functionality of bundled library is lost.
But my main concern is the conflict between ruby and gem executables, since it makes packaging for Linux distributions hard (for Fedora and RHEL in my case).